文章
Miss Chen
2018年03月27日
Description: This perennial wildflower is ½–1½' tall, sending up one or more unbranched leafy stems from the root system. These stems are erect, ascending, or sprawling; they are light green, tan, or reddish brown, terete, and canescent. Along each stem, there are densely spaced alternate leaves that appear to be whorled (pointing in all directions). Individual leaves are ¾–1½" long and 1/8" (3 mm.) across; they are linear in shape, smooth along their margins, stiff, and sessile (or nearly so). The upper surfaces of the leaves are medium to dark green and glabrous, while their lower surfaces are pale green and canescent. Each leaf has a prominent midvein.
The central stem terminates in a small cluster of flowerheads (sometimes only a single flowerhead is produced, but there are usually more). Individual flowerheads are born on unbranched peduncles about ½–2" long (rarely, they are longer). Along each peduncle, there are small bracts up to ¼" long that resemble the leaves, except they are much smaller in size. The daisy-like flowerheads span ¾–1¼" across, consisting of 10-20 ray florets and a similar number of disk florets. The petal-like rays are lavender or pale blue-violet, while the tiny corollas of the disk florets are bright yellow, later becoming orange-red. At the base of each flowerhead, there are 4-5 series of appressed floral bracts. Individual floral bracts are scale-like in appearance and linear-oblong in shape; each of these bracts is medium green along the upper one-half of its length, otherwise it is nearly white. The blooming period occurs from early to mid-fall and lasts about 1 month. Both disk and ray florets produce achenes.Stem & Leaves The small achenes are bullet-shaped and pubescent; there is a small tuft of hairs at the apex of each achene. For each tuft, the spreading inner hairs are long, while the outer hairs are short. The tufted achenes are distributed by the wind. The root system forms a caudex with fibrous roots; sometimes, spreading rhizomes are produced, from which vegetative offsets can develop.
Cultivation: The preference is full or partial sun, dry-mesic conditions, and an acidic soil that is sandy or rocky. This wildflower can be cultivated in rock gardens.
Range & Habitat: The native Flax-Leaved Aster is occasional in the northern half of Illinois, while in the southern half of the state it is rare or absent (see Distribution Map). Habitats include upland sand prairies, upland sandy savannas, stabilized sand dunes, open rocky woodlands, rocky wooded slopes, and sandstone glades. This wildflower is found in high quality natural habitats with sparse ground cover. It benefits from occasional wildfires in wooded areas, as this reduces the encroachment of woody vegetation.
Faunal Associations: The nectar and pollen of the flowerheads attract many kinds of insects, including long-tongued bees, short-tongued bees, various flies, butterflies, skippers, and beetles. Several bees are pollinator specialists (oligoleges) of Aster spp. (Asters): Andrena asteris, Andrena asteroides, Andrena hirticincta, Andrena nubecula, Andrena simplex, Andrena solidaginis, and Colletes simulans armata. Some of these bees are also oligoleges of Solidago spp. (Goldenrods). Other insects feed on the leaves, flowers, seeds, plant juices, stalks, or roots of Asters. These species include the plant bug Plagiognathus cuneatus, the leafhopper Macrosteles quadrilineatus, Exema canadensis and other leaf beetles, the long-horned beetle Mecas pergrata, several aphids (mainly Uroleucon spp.), and caterpillars of the butterflies Chlosyne nycteis (Silvery Checkerspot) and Phyciodes tharos (Pearl Crescent). There are also many moth species whose caterpillars feed on Asters (see Moth Table). Among vertebrate animals, the Ruffed Grouse and Wild Turkey eat the leaves and seeds, while the Cottontail Rabbit and White-Tailed Deer browse on the foliage. The White-Footed Mouse and possibly other small rodents also eat the seeds.
Photographic Location: An upland sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: This wildflower has an elegant appearance. What distinguishes Flax-Leaved Aster from species in the Aster genus are the tufted hairs of its achenes: they consist of a combination of long and short hairs, rather than hairs of uniform length. Nonetheless, it is sometimes referred to as Aster linariifolius because of its similarity to these species in other respects. Flax-Leaved Aster superficially resembles Aster oblongifolius (Aromatic Aster) to some extent, but it has unbranched stems, while the latter species has abundantly branched stems. Because of its short linear leaves, which are arranged in dense pseudo-whorls, Flax-Leaved Aster is relatively easy to identify. Another common name of this species is Stiff-Leaved Aster.
The central stem terminates in a small cluster of flowerheads (sometimes only a single flowerhead is produced, but there are usually more). Individual flowerheads are born on unbranched peduncles about ½–2" long (rarely, they are longer). Along each peduncle, there are small bracts up to ¼" long that resemble the leaves, except they are much smaller in size. The daisy-like flowerheads span ¾–1¼" across, consisting of 10-20 ray florets and a similar number of disk florets. The petal-like rays are lavender or pale blue-violet, while the tiny corollas of the disk florets are bright yellow, later becoming orange-red. At the base of each flowerhead, there are 4-5 series of appressed floral bracts. Individual floral bracts are scale-like in appearance and linear-oblong in shape; each of these bracts is medium green along the upper one-half of its length, otherwise it is nearly white. The blooming period occurs from early to mid-fall and lasts about 1 month. Both disk and ray florets produce achenes.Stem & Leaves The small achenes are bullet-shaped and pubescent; there is a small tuft of hairs at the apex of each achene. For each tuft, the spreading inner hairs are long, while the outer hairs are short. The tufted achenes are distributed by the wind. The root system forms a caudex with fibrous roots; sometimes, spreading rhizomes are produced, from which vegetative offsets can develop.
Cultivation: The preference is full or partial sun, dry-mesic conditions, and an acidic soil that is sandy or rocky. This wildflower can be cultivated in rock gardens.
Range & Habitat: The native Flax-Leaved Aster is occasional in the northern half of Illinois, while in the southern half of the state it is rare or absent (see Distribution Map). Habitats include upland sand prairies, upland sandy savannas, stabilized sand dunes, open rocky woodlands, rocky wooded slopes, and sandstone glades. This wildflower is found in high quality natural habitats with sparse ground cover. It benefits from occasional wildfires in wooded areas, as this reduces the encroachment of woody vegetation.
Faunal Associations: The nectar and pollen of the flowerheads attract many kinds of insects, including long-tongued bees, short-tongued bees, various flies, butterflies, skippers, and beetles. Several bees are pollinator specialists (oligoleges) of Aster spp. (Asters): Andrena asteris, Andrena asteroides, Andrena hirticincta, Andrena nubecula, Andrena simplex, Andrena solidaginis, and Colletes simulans armata. Some of these bees are also oligoleges of Solidago spp. (Goldenrods). Other insects feed on the leaves, flowers, seeds, plant juices, stalks, or roots of Asters. These species include the plant bug Plagiognathus cuneatus, the leafhopper Macrosteles quadrilineatus, Exema canadensis and other leaf beetles, the long-horned beetle Mecas pergrata, several aphids (mainly Uroleucon spp.), and caterpillars of the butterflies Chlosyne nycteis (Silvery Checkerspot) and Phyciodes tharos (Pearl Crescent). There are also many moth species whose caterpillars feed on Asters (see Moth Table). Among vertebrate animals, the Ruffed Grouse and Wild Turkey eat the leaves and seeds, while the Cottontail Rabbit and White-Tailed Deer browse on the foliage. The White-Footed Mouse and possibly other small rodents also eat the seeds.
Photographic Location: An upland sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: This wildflower has an elegant appearance. What distinguishes Flax-Leaved Aster from species in the Aster genus are the tufted hairs of its achenes: they consist of a combination of long and short hairs, rather than hairs of uniform length. Nonetheless, it is sometimes referred to as Aster linariifolius because of its similarity to these species in other respects. Flax-Leaved Aster superficially resembles Aster oblongifolius (Aromatic Aster) to some extent, but it has unbranched stems, while the latter species has abundantly branched stems. Because of its short linear leaves, which are arranged in dense pseudo-whorls, Flax-Leaved Aster is relatively easy to identify. Another common name of this species is Stiff-Leaved Aster.
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文章
Miss Chen
2018年03月27日
Description: This perennial vine is up to 30' long; it dies back to the ground each year. The stems are light green or light tan, stout, and smooth to prickly-bristly. The opposite leaves are up to 6" long and 4" across; smaller leaves are usually oval-cordate in shape, but larger leaves are palmate with 3 lobes (rarely with 5). These leaves have a rough texture and coarse serration along the margins; they are medium green or yellowish green on their upper surfaces, and whitish green below. The long petioles are light green or light tan, stout, and prickly-bristly. At the base of each petiole is a pair of lanceolate stipules. The hairiness or pubescence of the stems and leaves is variable, if it is present at all. Usually, there are small white hairs along the major veins on the leaf undersides; sometimes these veins are also prickly. American Hops is dioecious, with male (staminate) and female (pistillate) plants. The male plants produce drooping panicles of staminate flowers. These panicles are up to 12" long and 6" across; they contain numerous small flowers that are yellowish or whitish green. Each staminate flower has 5 sepals, 5 stamens, and no petals. It has a star-like appearance and spans about ¼" across, hanging downward from a slender pedicel that is often slightly pubescent. The non-sticky pollen is produced in great abundance and it is easily dispersed into the air.
The female plants produce odd-looking cone-shaped spikes of pistillate flowers (aments) from the axils of the leaves. A spike of pistillate flowers is up to 3" long, 2" across, and ovoid in shape; it usually hangs downward from a slender peduncle. The pistillate spike consists of overlapping green bracts that are ovate; there is a pair of pistillate flowers tucked between each adjacent pair of bracts. Each pistillate flower consists of little more than an ovary with a sticky stigma that is long and slender. Both the male and female flowers bloom during the late summer for about 2 weeks. The male flowers quickly turn brown and wither away, while the fruits (or aments) of the female flowers persist longer and gradually turn brown. Each pistillate flower produces a capsule with a single seed that is resinous and aromatic. This vine reproduces by reseeding itself.
Cultivation: The preference is partial or full sun, fertile soil, and moist to slightly dry conditions. This robust vine will also grow in poor soil that is rocky or gravelly. It can be quite aggressive and appears to have few problems with disease.
Range & Habitat: The native American Hops is a common plant that occurs in most areas of central and northern Illinois. However, it less common or absent from many areas of southern Illinois (see Distribution Map). Other varieties of this vine also occur in Eurasia. American Hops occurs in openings of both upland and floodplain forests, woodland borders, thickets, and slopes of bluffs. In more developed areas, it is found along fence rows, vacant lots, areas along railroads, and miscellaneous waste areas. This plant favors areas that are more or less disturbed, whether from human activities or natural causes. It often clambers over surrounding vegetation, including shrubs and small trees.
Faunal Associations: Pollination is by wind, rather than insects. However, the abundant pollen of the staminate flowers attracts flower flies (Syrphidae) and small bees. The caterpillars of several butterflies feed on hops (Humulus spp.), including Vanessa atalanta (Red Admiral), Polygonia interrogationis (Question Mark), Polygonia comma (Comma), and Strymon melinus (Gray Hairstreak). The caterpillars of the latter species feed on the fruits and developing seeds. The caterpillars of some moths also feed on hops; they include Eudryas grata (Beautiful Wood Nymph), Hydraecia immanis (Hop Vine Borer Moth), Hypena humuli (Hop Looper), and Cnephasia longana (Omnivorous Leaftier). Other insect feeders include Taedia hawleyi (Hop Plant Bug), Phorodon humuli (Hop Aphid), Psylliodes punctulata (Hop Flea Beetle), larvae of Lasioptera humulicaulis (Hop Stem Gall Midge), and the thrips Neohydatothrips beachae. Little information appears to be available about this vine's relationships to vertebrate animals, however it undoubtedly provides protective cover for many species of birds and mammals.
Photographic Location: A sunny area along an abandoned railroad in Urbana, Illinois. This vine also occurred in partially shaded areas at the same locality.
Comments: American Hops has some resemblance to grapevines (Vitis spp.), but it is a coarser and more bristly vine that flowers late in the year, while the latter flowers during the spring. The female fruit of hops is used to flavor beer and prevent decay during fermentation from bacterial processes. It is possible that the wind-dispersed pollen may cause allergic reactions in some people. There are both European and American varieties of this species, and it is quite possible that they have interbred in the wild. Consequently, they are often hard to distinguish. There is a variety of American Hops that has unlobed leaves. There is an invasive non-native species of hops that occurs in the wild, Humulus japonicus (Japanese Hops). This is an annual vine that has leaves with more lobes (5-7) than American Hops. Furthermore, the lobes of its leaves are more narrow and pointed.
The female plants produce odd-looking cone-shaped spikes of pistillate flowers (aments) from the axils of the leaves. A spike of pistillate flowers is up to 3" long, 2" across, and ovoid in shape; it usually hangs downward from a slender peduncle. The pistillate spike consists of overlapping green bracts that are ovate; there is a pair of pistillate flowers tucked between each adjacent pair of bracts. Each pistillate flower consists of little more than an ovary with a sticky stigma that is long and slender. Both the male and female flowers bloom during the late summer for about 2 weeks. The male flowers quickly turn brown and wither away, while the fruits (or aments) of the female flowers persist longer and gradually turn brown. Each pistillate flower produces a capsule with a single seed that is resinous and aromatic. This vine reproduces by reseeding itself.
Cultivation: The preference is partial or full sun, fertile soil, and moist to slightly dry conditions. This robust vine will also grow in poor soil that is rocky or gravelly. It can be quite aggressive and appears to have few problems with disease.
Range & Habitat: The native American Hops is a common plant that occurs in most areas of central and northern Illinois. However, it less common or absent from many areas of southern Illinois (see Distribution Map). Other varieties of this vine also occur in Eurasia. American Hops occurs in openings of both upland and floodplain forests, woodland borders, thickets, and slopes of bluffs. In more developed areas, it is found along fence rows, vacant lots, areas along railroads, and miscellaneous waste areas. This plant favors areas that are more or less disturbed, whether from human activities or natural causes. It often clambers over surrounding vegetation, including shrubs and small trees.
Faunal Associations: Pollination is by wind, rather than insects. However, the abundant pollen of the staminate flowers attracts flower flies (Syrphidae) and small bees. The caterpillars of several butterflies feed on hops (Humulus spp.), including Vanessa atalanta (Red Admiral), Polygonia interrogationis (Question Mark), Polygonia comma (Comma), and Strymon melinus (Gray Hairstreak). The caterpillars of the latter species feed on the fruits and developing seeds. The caterpillars of some moths also feed on hops; they include Eudryas grata (Beautiful Wood Nymph), Hydraecia immanis (Hop Vine Borer Moth), Hypena humuli (Hop Looper), and Cnephasia longana (Omnivorous Leaftier). Other insect feeders include Taedia hawleyi (Hop Plant Bug), Phorodon humuli (Hop Aphid), Psylliodes punctulata (Hop Flea Beetle), larvae of Lasioptera humulicaulis (Hop Stem Gall Midge), and the thrips Neohydatothrips beachae. Little information appears to be available about this vine's relationships to vertebrate animals, however it undoubtedly provides protective cover for many species of birds and mammals.
Photographic Location: A sunny area along an abandoned railroad in Urbana, Illinois. This vine also occurred in partially shaded areas at the same locality.
Comments: American Hops has some resemblance to grapevines (Vitis spp.), but it is a coarser and more bristly vine that flowers late in the year, while the latter flowers during the spring. The female fruit of hops is used to flavor beer and prevent decay during fermentation from bacterial processes. It is possible that the wind-dispersed pollen may cause allergic reactions in some people. There are both European and American varieties of this species, and it is quite possible that they have interbred in the wild. Consequently, they are often hard to distinguish. There is a variety of American Hops that has unlobed leaves. There is an invasive non-native species of hops that occurs in the wild, Humulus japonicus (Japanese Hops). This is an annual vine that has leaves with more lobes (5-7) than American Hops. Furthermore, the lobes of its leaves are more narrow and pointed.
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文章
Miss Chen
2018年03月27日
Description: This perennial herbaceous wildflower is 3–6½' tall, sending up one or more erect leafy stems from its root system. The stems are light green, faded light yellow, or faded light brown; they are terete, stiffly short-pubescent, and sparingly branched above. Most of the leaves are located along the lower half of the primary stems, where they are opposite. Smaller alternate leaves occur sparingly along the upper primary and secondary stems. All of these stems are erect to ascending. The lower to middle leaves are up to 6" long and 5" across; they are broadly oblong to oval-ovate in shape with margins that are slightly serrated to doubly serrated. To a limited extent, the leaf margins are also horizontally undulate. The leaves abruptly contract to narrowly winged petioles up to 2" long. These petioles have short stiff hairs. The leaf blades are medium green or yellowish green above, and light green below. The upper blade surface is sparsely covered with minute stiff hairs, providing it with a rough texture. The lower blade surface has short stiff hairs along the primary veins and a sparse covering of minute stiff hairs between the veins. The leaves have a prominent central vein and two prominent lateral veins; the latter curve toward the leaf tips.
The upper stems terminate in either solitary flowerheads or small loose clusters of 2-3 flowerheads on long naked peduncles up to 1' long. These flowerheads tend to occur at different heights from the ground. The peduncles are similar to the stems, except they are a little more narrow in diameter. The flowerheads are held erect or at an angle facing partly upward; they span about 2-3" across. Each flowerhead has 10-20 ray florets and a central disk of numerous disk florets. The widely spreading petaloid rays are bright yellow and oblong in shape. The corollas of the disk florets are about 6 mm. (¼") long, tubular in shape with 5 upper lobes, and dark red above. The divided styles of the disk florets are bright yellow, while their tubular anthers are dark red. The ray florets are sterile, while the disk florets are perfect. Surrounding the base of each flowerhead, there are floral bracts (phyllaries) in 3 series; these bracts differ in size and they are appressed together. Individual floral bracts are light green and broadly oblong in shape; their tips are obtusely pointed or rounded. The margins of these bracts are toothless and ciliate; their outer surfaces between the margins are sparsely short-pubescent.
The blooming period occurs during early autumn, lasting about 3-4 weeks. Afterwards, fertile disk florets are replaced achenes about 4 mm. in length. These achenes are oblong-obovate, somewhat flattened, brown, and short-pubescent primarily toward their apices. Each achene has a pair of lanceolate scales about 2 mm. long at its apex. However, these scales are early-deciduous. Because the seeds are dispersed primarily by gravity, they usually do not travel far from the mother plant. The root system consists of a crown of fibrous roots and short rhizomes. Clonal offsets are produced sparingly from the short rhizomes.
Cultivation: This plant prefers full or partial sun and mesic to dry-mesic conditions; it adapts to different soil types, including those that contain sand, loam, clay, and rocky material. It is easy to cultivate this plant in gardens and it remains more or less erect, rather than flopping over. Because of its short rhizomes, it is a less aggressive spreader than some sunflower species.
Range & Habitat: Silphium Sunflower has been found in only 2 counties of southern Illinois (Alexander and St. Clair counties), where it is native and rare (see Distribution Map). It may be extirpated from Alexander county, but several populations of this plant still persist in St. Clair county. Illinois lies along the northern range-limit of this species. Silphium Sunflower is endemic to south-central and central United States, where it is found primarily in Arkansas, Missouri, and Tennessee. Habitats include sand prairies, upland prairies and glades, upland savannas, openings in rocky woodlands, low sandy ground along streams, roadsides, and fallow fields. This sunflower is found in both high quality natural areas and disturbed sites. In wooded habitats, it benefits from occasional wildfires. Destruction of habitat by development and invasion of exotic species are the primary threats to this rare plant in Illinois (Molano-Flores, 2004).
Faunal Association: While little is known about floral-faunal relationships for this particular sunflower species, considerable information is available about other sunflower species and sunflowers in general. Similar species of sunflowers attract such flower-visiting insects as bumblebees, long-horned bees (Melissodes spp.), leaf-cutter bees (Megachile spp.), Halictid bees (Agapostemon spp., Lasioglossum spp.), Andrenid bees (Andrena spp.), dagger bees (Heterosarus spp.), plasterer bees (Colletes spp.), cuckoo bees (Epeolus spp., Triepeolus spp.), miscellaneous wasps, Syrphid flies (Eristalis spp., Toxomerus spp.), bee flies (Exoprosopa spp.), miscellaneous butterflies, and miscellaneous skippers (Robertson, 1929, and others). Some bees are specialist pollinators (oligoleges) of sunflowers; they include Melissodes agilis, Dufourea marginata, Andrena accepta, Andrena aliciae, Andrena helianthi, and Pseudopanurgus rugosus. Other insects feed destructively on the leaves, stems, roots, seeds, and florets of sunflowers. These species include weevils, long-horned beetles, leaf beetles, billbugs, seed weevils, larvae of leaf-miner flies, larvae of gall midges, plant bugs, aphids, treehoppers, mealybugs, larvae of Tortricid moths, larvae of Noctuid moths, larvae of other moths, grasshoppers, and flower thrips. The caterpillars of some butterflies feed on sunflowers; these species include Chlosyne gorgone (Gorgon Checkerspot), Chlosyne nycteis (Silvery Checkerspot), and Vanessa cardui (Painted Lady); see Bouseman & Sternburg, 2001; Charlet & Gavloski, 2011. Some vertebrate animals use sunflowers as a source of food. Upland gamebirds and songbirds eat their nutritious seeds; the Mourning Dove, Bobwhite Quail, American Crow, Eastern Goldfinch, Common Grackle, Eastern Meadowlark, White-breasted Nuthatch, and various sparrows are examples of such birds (Lewis, 1993; Martin et al., 1951/1961). White-tailed Deer and domesticated grazing animals like to feed on the young stems and leaves of these plants (Georgia, 1913; Martin et al., 1951/1961). The seeds of sunflowers are dispersed to a limited extent by birds; sometimes they drop the seeds during flight before they consume them.
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: The Silphium Sunflower (Helianthus silphioides) is often overlooked in wildflower guidebooks and it is little-known by members of the public. This is partly because, for a long time, this sunflower was considered a variety of the Purple-disk Sunflower (Helianthus atrorubens). However, the Silphium Sunflower differs from the latter by having fewer long hairs on its stems, more narrow and less winged petioles, and achenes that are pubescent primarily toward their apices, rather than throughout. The Purple-disk Sunflower is found primarily in SE United States; it does not occur in Illinois. Scientific synonyms of the Silphium Sunflower include Helianthus atrorubens pubescens and Helianthus kentuckiensis. Other common names of this sunflower include Rosinweed Sunflower and Ozark Sunflower. The common names, Silphium Sunflower and Rosinweed Sunflower, refer to the superficial similarity of this sunflower to the prairie wildflower, Silphium integrifolium (Rosinweed). It also resembles Heliopsis helianthoides (False Sunflower) to a significant extent, but the flowerheads of Silphium Sunflower are borne on longer naked stalks than those of the False Sunflower, and it usually blooms later in the year than the latter species.
The upper stems terminate in either solitary flowerheads or small loose clusters of 2-3 flowerheads on long naked peduncles up to 1' long. These flowerheads tend to occur at different heights from the ground. The peduncles are similar to the stems, except they are a little more narrow in diameter. The flowerheads are held erect or at an angle facing partly upward; they span about 2-3" across. Each flowerhead has 10-20 ray florets and a central disk of numerous disk florets. The widely spreading petaloid rays are bright yellow and oblong in shape. The corollas of the disk florets are about 6 mm. (¼") long, tubular in shape with 5 upper lobes, and dark red above. The divided styles of the disk florets are bright yellow, while their tubular anthers are dark red. The ray florets are sterile, while the disk florets are perfect. Surrounding the base of each flowerhead, there are floral bracts (phyllaries) in 3 series; these bracts differ in size and they are appressed together. Individual floral bracts are light green and broadly oblong in shape; their tips are obtusely pointed or rounded. The margins of these bracts are toothless and ciliate; their outer surfaces between the margins are sparsely short-pubescent.
The blooming period occurs during early autumn, lasting about 3-4 weeks. Afterwards, fertile disk florets are replaced achenes about 4 mm. in length. These achenes are oblong-obovate, somewhat flattened, brown, and short-pubescent primarily toward their apices. Each achene has a pair of lanceolate scales about 2 mm. long at its apex. However, these scales are early-deciduous. Because the seeds are dispersed primarily by gravity, they usually do not travel far from the mother plant. The root system consists of a crown of fibrous roots and short rhizomes. Clonal offsets are produced sparingly from the short rhizomes.
Cultivation: This plant prefers full or partial sun and mesic to dry-mesic conditions; it adapts to different soil types, including those that contain sand, loam, clay, and rocky material. It is easy to cultivate this plant in gardens and it remains more or less erect, rather than flopping over. Because of its short rhizomes, it is a less aggressive spreader than some sunflower species.
Range & Habitat: Silphium Sunflower has been found in only 2 counties of southern Illinois (Alexander and St. Clair counties), where it is native and rare (see Distribution Map). It may be extirpated from Alexander county, but several populations of this plant still persist in St. Clair county. Illinois lies along the northern range-limit of this species. Silphium Sunflower is endemic to south-central and central United States, where it is found primarily in Arkansas, Missouri, and Tennessee. Habitats include sand prairies, upland prairies and glades, upland savannas, openings in rocky woodlands, low sandy ground along streams, roadsides, and fallow fields. This sunflower is found in both high quality natural areas and disturbed sites. In wooded habitats, it benefits from occasional wildfires. Destruction of habitat by development and invasion of exotic species are the primary threats to this rare plant in Illinois (Molano-Flores, 2004).
Faunal Association: While little is known about floral-faunal relationships for this particular sunflower species, considerable information is available about other sunflower species and sunflowers in general. Similar species of sunflowers attract such flower-visiting insects as bumblebees, long-horned bees (Melissodes spp.), leaf-cutter bees (Megachile spp.), Halictid bees (Agapostemon spp., Lasioglossum spp.), Andrenid bees (Andrena spp.), dagger bees (Heterosarus spp.), plasterer bees (Colletes spp.), cuckoo bees (Epeolus spp., Triepeolus spp.), miscellaneous wasps, Syrphid flies (Eristalis spp., Toxomerus spp.), bee flies (Exoprosopa spp.), miscellaneous butterflies, and miscellaneous skippers (Robertson, 1929, and others). Some bees are specialist pollinators (oligoleges) of sunflowers; they include Melissodes agilis, Dufourea marginata, Andrena accepta, Andrena aliciae, Andrena helianthi, and Pseudopanurgus rugosus. Other insects feed destructively on the leaves, stems, roots, seeds, and florets of sunflowers. These species include weevils, long-horned beetles, leaf beetles, billbugs, seed weevils, larvae of leaf-miner flies, larvae of gall midges, plant bugs, aphids, treehoppers, mealybugs, larvae of Tortricid moths, larvae of Noctuid moths, larvae of other moths, grasshoppers, and flower thrips. The caterpillars of some butterflies feed on sunflowers; these species include Chlosyne gorgone (Gorgon Checkerspot), Chlosyne nycteis (Silvery Checkerspot), and Vanessa cardui (Painted Lady); see Bouseman & Sternburg, 2001; Charlet & Gavloski, 2011. Some vertebrate animals use sunflowers as a source of food. Upland gamebirds and songbirds eat their nutritious seeds; the Mourning Dove, Bobwhite Quail, American Crow, Eastern Goldfinch, Common Grackle, Eastern Meadowlark, White-breasted Nuthatch, and various sparrows are examples of such birds (Lewis, 1993; Martin et al., 1951/1961). White-tailed Deer and domesticated grazing animals like to feed on the young stems and leaves of these plants (Georgia, 1913; Martin et al., 1951/1961). The seeds of sunflowers are dispersed to a limited extent by birds; sometimes they drop the seeds during flight before they consume them.
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: The Silphium Sunflower (Helianthus silphioides) is often overlooked in wildflower guidebooks and it is little-known by members of the public. This is partly because, for a long time, this sunflower was considered a variety of the Purple-disk Sunflower (Helianthus atrorubens). However, the Silphium Sunflower differs from the latter by having fewer long hairs on its stems, more narrow and less winged petioles, and achenes that are pubescent primarily toward their apices, rather than throughout. The Purple-disk Sunflower is found primarily in SE United States; it does not occur in Illinois. Scientific synonyms of the Silphium Sunflower include Helianthus atrorubens pubescens and Helianthus kentuckiensis. Other common names of this sunflower include Rosinweed Sunflower and Ozark Sunflower. The common names, Silphium Sunflower and Rosinweed Sunflower, refer to the superficial similarity of this sunflower to the prairie wildflower, Silphium integrifolium (Rosinweed). It also resembles Heliopsis helianthoides (False Sunflower) to a significant extent, but the flowerheads of Silphium Sunflower are borne on longer naked stalks than those of the False Sunflower, and it usually blooms later in the year than the latter species.
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文章
Miss Chen
2018年03月26日
Description: This perennial wildflower is about 3-5' tall; it is erect and branches occasionally. The stems are light green, pale reddish green, or purple; the upper stems have short bristly hairs, while lower stems are glabrous and sometimes glaucous. The lower and middle leaves are opposite, while the upper leaves are alternate; they spread outward from the stems. The leaf blades are up to 7" long and 3" across; they are broadly lanceolate to ovate with long slender tips and sharply serrated margins. The upper surface of each leaf is dark green and rough in texture, while the lower surface is light green and nearly hairless. The petioles of the leaves are about ½–1½" long; they are somewhat winged near the leaf blade, but become more narrow toward the stem. The upper stems terminate in yellow flowerheads on naked stalks (peduncles) of varying length. Each flowerhead is about 2–3½" across, consisting of 8-12 ray florets that surround numerous disk florets in a central disk. The petal-like ray florets are bright yellow and oblong in shape, while the disk florets are yellow and tubular. The base of each flowerhead consists of several overlapping bracts. These floral bracts are light green, linear-lanceolate, and ciliate along their margins; they often curve backward. The blooming period occurs from mid-summer to early fall and lasts about 1–1½ months. Each fertile floret is replaced by a dark achene about 1/8" (3 mm.) in length (or a little longer) that is oblongoid and slightly flattened. The root system is fibrous and rhizomatous. Vegetative colonies of plants are often formed from the rhizomes.
Cultivation: The preference is partial sun or dappled sunlight, moist to mesic conditions, and a rich loamy soil. Like other perennial sunflowers, this species may spread aggressively in some situations.
Range & Habitat: The native Ten-Petal Sunflower is occasional in Illinois and widely scattered throughout the state; it is largely absent in south-central Illinois (see Distribution Map). Habitats include open woodlands, woodland borders, savannas, partially shaded areas along rivers, meadows, and thickets. Occasional disturbance is beneficial if it prevents excessive shade from overhead trees.
Faunal Associations: The flowerheads attract many kinds of insects, especially bees (both long-tongued & short-tongued), which suck nectar and collect pollen from the florets. Other visitors include butterflies, wasps, and various kinds of flies. An impressive variety of insects feed on various parts of Helianthus spp. (Sunflowers), including beetles, weevils, and the caterpillars of some butterflies and moths (see Insect Table for some examples). The seeds are an attractive source of food to many upland gamebirds and granivorous songbirds (see Bird Table). Muskrats occasionally feed on the leaves and stems; they use the latter in the construction of their lodges in wetlands. Young plants are occasionally eaten by rabbits, deer, and groundhogs; they are also palatable to many kinds of livestock.
Photographic Location: A woodland opening at Meadowbrook Park in Urbana. The long slender bracts of a flowerbud can be seen in the upper leaf corner of the upper photograph. In the lower left of the same photograph, the long slender tip of a leaf blade is fully visible. Both photographs show the long pointed teeth along the margins of the leaf blades.
Comments: This is an attractive woodland sunflower that should be cultivated in gardens more often. There are many species of sunflowers in Illinois (both prairie and woodland) and they are often difficult to identify. Ten-Petal Sunflower has the following characteristics that are useful in identifying this species: 1) the margins of its leaf blades have teeth that are long and pointed, 2) the tips of its leaf blades are unusually long and slender, and 3) the floral bracts are unusually long and slender. However, some populations of plants may have shorter teeth on the leaf margins.
Cultivation: The preference is partial sun or dappled sunlight, moist to mesic conditions, and a rich loamy soil. Like other perennial sunflowers, this species may spread aggressively in some situations.
Range & Habitat: The native Ten-Petal Sunflower is occasional in Illinois and widely scattered throughout the state; it is largely absent in south-central Illinois (see Distribution Map). Habitats include open woodlands, woodland borders, savannas, partially shaded areas along rivers, meadows, and thickets. Occasional disturbance is beneficial if it prevents excessive shade from overhead trees.
Faunal Associations: The flowerheads attract many kinds of insects, especially bees (both long-tongued & short-tongued), which suck nectar and collect pollen from the florets. Other visitors include butterflies, wasps, and various kinds of flies. An impressive variety of insects feed on various parts of Helianthus spp. (Sunflowers), including beetles, weevils, and the caterpillars of some butterflies and moths (see Insect Table for some examples). The seeds are an attractive source of food to many upland gamebirds and granivorous songbirds (see Bird Table). Muskrats occasionally feed on the leaves and stems; they use the latter in the construction of their lodges in wetlands. Young plants are occasionally eaten by rabbits, deer, and groundhogs; they are also palatable to many kinds of livestock.
Photographic Location: A woodland opening at Meadowbrook Park in Urbana. The long slender bracts of a flowerbud can be seen in the upper leaf corner of the upper photograph. In the lower left of the same photograph, the long slender tip of a leaf blade is fully visible. Both photographs show the long pointed teeth along the margins of the leaf blades.
Comments: This is an attractive woodland sunflower that should be cultivated in gardens more often. There are many species of sunflowers in Illinois (both prairie and woodland) and they are often difficult to identify. Ten-Petal Sunflower has the following characteristics that are useful in identifying this species: 1) the margins of its leaf blades have teeth that are long and pointed, 2) the tips of its leaf blades are unusually long and slender, and 3) the floral bracts are unusually long and slender. However, some populations of plants may have shorter teeth on the leaf margins.
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Miss Chen
2018年03月26日
Description: This herbaceous perennial plant is 1½–2½' tall, branching occasionally. The round stems are light green and covered with coarse spreading hairs. Both basal and cauline leaves are produced; the cauline leaves are alternate, becoming smaller as they ascend the stems. The basal and lower cauline leaves are oddly pinnate (often with 5 leaflets), while the upperFlower, Stems, & Leaves cauline leaves are trifoliate or simple. The simple leaves and leaflets of the compound leaves are up to 3" long and 2½" across. They are lanceolate to ovate-oval, coarsely serrated or shallowly cleft along the margins, and largely hairless. Sometimes the leaves and leaflets are deeply cleft into 2 or 3 lobes. The terminal leaflet is larger in size than the lateral leaflets. The basal and lower cauline leaves have stout petioles, while the upper cauline leaves are nearly sessile. At the base of each petiole, there is a pair of leafy stipules that are cleft or dentate; each stipule is up to ½" long. The upper stems individually terminate in 1-3 flowers; sometimes single flowers are produced from the axils of the upper leaves. Each flower develops from a stalk (peduncle) up to 3" long; this stalk is covered with coarse spreading hairs. Each flower is about ½" across, consisting of 5 petals that are white or cream, 5 triangular green sepals, and several stamens surrounding a large cluster of green carpels with elongated styles. The petals are shorter than the sepals. The anthers are usually dull yellow or tan. The receptacle of the flower (underneath the carpels) is hairless or nearly so. The blooming period occurs from late spring to mid-summer and lasts about a month. There is no noticeable floral scent. Each flower is replaced by a spheroid cluster of achenes with elongated styles that are hooked at their tips. This fruiting cluster is about ¾" across; it is initially green, but eventually turns brown. The root system consists of a taproot and rhizomes; vegetative offsets are often formed.
Cultivation: The preference is partial sun, moist to mesic conditions, and soil containing loam or sandy loam. Full sun and light shade are also tolerated.
Range & Habitat: The native Rough Avens occurs occasionally in central and northern Illinois, but it is absent from the southern and southwestern areas of the state (see Distribution Map). Habitats include savannas, thickets, woodland borders, and moist meadows. Sometimes it is found in thickets and prairie remnants along railroads and roadsides.
Faunal Associations: Information about floral-faunal relationships for this species is rather limited. They are probably similar to those of Geum canadense (White Avens). The nectar and pollen of the flowers probably attract small bees, wasps, and flies. Insects that feed on the foliage of Geum spp. (Avens) include the aphids Acyrthosiphon pseudodirhodum, Macrosiphum gei, Macrosiphum pallidum, and Macrosiphum pseudorosae. In addition, larvae of a moth, Tinagma obscurofasciella, mine the leaves. The achenes with hooked styles can cling to the fur of mammals, feathers of birds, and clothing of humans; by this means, they can be distributed across considerable distances.
Photographic Location: Between a thicket and prairie remnant along a railroad in Champaign County, Illinois.
Comments: Rough Avens blooms a little later than Geum vernum (Spring Avens), but a little earlier than Geum canadense (White Avens) and Geum virginianum (Pale Avens). It can be confused with White Avens. However, Rough Avens has petals that are shorter than the sepals and its flowering stalks have coarse spreading hairs. White Avens has petals that are as long or longer than the sepals and its flowering stalks are finely pubescent. Pale Avens also has an appearance that is similar to Rough Avens; it is restricted to southern Illinois. Pale Avens has slightly smaller flowers (about 1/3" across) with cream petals that are much shorter than the sepals. The receptacles of its flowers are bristly-hairy, while the receptacles of Rough Avens are hairless or nearly so.
Cultivation: The preference is partial sun, moist to mesic conditions, and soil containing loam or sandy loam. Full sun and light shade are also tolerated.
Range & Habitat: The native Rough Avens occurs occasionally in central and northern Illinois, but it is absent from the southern and southwestern areas of the state (see Distribution Map). Habitats include savannas, thickets, woodland borders, and moist meadows. Sometimes it is found in thickets and prairie remnants along railroads and roadsides.
Faunal Associations: Information about floral-faunal relationships for this species is rather limited. They are probably similar to those of Geum canadense (White Avens). The nectar and pollen of the flowers probably attract small bees, wasps, and flies. Insects that feed on the foliage of Geum spp. (Avens) include the aphids Acyrthosiphon pseudodirhodum, Macrosiphum gei, Macrosiphum pallidum, and Macrosiphum pseudorosae. In addition, larvae of a moth, Tinagma obscurofasciella, mine the leaves. The achenes with hooked styles can cling to the fur of mammals, feathers of birds, and clothing of humans; by this means, they can be distributed across considerable distances.
Photographic Location: Between a thicket and prairie remnant along a railroad in Champaign County, Illinois.
Comments: Rough Avens blooms a little later than Geum vernum (Spring Avens), but a little earlier than Geum canadense (White Avens) and Geum virginianum (Pale Avens). It can be confused with White Avens. However, Rough Avens has petals that are shorter than the sepals and its flowering stalks have coarse spreading hairs. White Avens has petals that are as long or longer than the sepals and its flowering stalks are finely pubescent. Pale Avens also has an appearance that is similar to Rough Avens; it is restricted to southern Illinois. Pale Avens has slightly smaller flowers (about 1/3" across) with cream petals that are much shorter than the sepals. The receptacles of its flowers are bristly-hairy, while the receptacles of Rough Avens are hairless or nearly so.
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Miss Chen
2018年03月26日
Description: This herbaceous perennial plant is about 1½–2½' tall, branching occasionally. The upper stems are light green and pubescent, while the lower stems are often brownish green and coarsely hairy. These stems are round in circumference, rather than angular. There are both basal leaves (produced during the spring) and alternate cauline leaves. The basal leaves are produced in a low rosette up to 6" across. The lower cauline leaves are trifoliate, while the upper cauline leaves are usually simple; they are rather variable in shape. Both simple leaves and leaflets of the compound leaves are up to 4" long and 3" across, becoming smaller as they ascend the stems. They are medium green, lanceolate to oval-ovate, coarsely serrated, and often cleft into 3 major lobes. Their margins are often shallowly cleft or incised as well.
The basal leaves are similar to the cauline leaves, except they are dark green and odd-pinnate with more than 3 leaflets. The wrinkled upper surface of each leaf is either hairless or it has scattered hairs that are very short and bristly; the lower surface is either hairless or it has a few hairs along the major veins. The lower leaves have stout petioles up to 1" long, while the upper leaves have either short petioles or they are sessile. At the base of each petiole, there are a pair of leafy stipules up to ½" long that are usually toothed along their margins. Each upper stem often terminates in an inflorescence of 1-3 flowers; sometimes individual flowers are produced from the axils of the upper leaves. The peduncles are up to 3" long and finely pubescent; they divide into shorter pedicels when there is more than one flower in the inflorescence.
Each flower is about ½" across, consisting of 5 bright white petals, 5 triangular green sepals, and numerous stamens surrounding a cluster of green carpels with elongated styles. The sepals are the same length or shorter than the petals; they are initially spreading, but curve downward with age. The anthers of the stamens are initially white, but they soon turn brown. The receptacle of each flower (the surface underneath the carpels) is pubescent. The blooming period occurs during the summer and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a spheroid cluster of achenes with persistent styles that are hooked at their tips. This fruiting cluster spans about ¾" across; it is initially green, but eventually turns brown. The root system consists of a taproot and rhizomes; from the latter, vegetative offsets can be produced. This plant occasionally forms loose colonies.
Cultivation: The preference is light shade or partial sun, moist to slightly dry conditions, and a loam or clay-loam soil. At favorable sites, this plant can spread aggressively and is somewhat weedy. White Avens is able to grow underneath Black Walnut trees (Juglans nigra) because of its tolerance to the phytotoxic chemicals that are released by the fallen leaves and roots of this tree.
Range & Habitat: The native White Avens is a common plant that occurs in every county of Illinois (see Distribution Map). Habitats include mesic deciduous woodlands, woodland borders, thickets, partially shaded seeps, fence rows with woody vegetation, powerline clearances in wooded areas, and edges of yards. Sometimes White Avens can be found in disturbed meadows and tall-grass prairies, but this is less typical. It adapts well to disturbed areas.
Faunal Associations: The flowers attract various insects, including bees, wasps, flies, and beetles. These insects suck nectar; some bees also collect pollen, while Syrphid flies often feed on the pollen. Insects that feed on the foliage of White Avens and other Aven species (Geum spp.) consist primarily of aphids, including Acyrthosiphon pseudodirhodum, Amphorophora rossi (White Avens is the preferred host plant), Macrosiphum gei, Macrosiphum pallidum, and Macrosiphon pseudorosae. In addition, the larvae of a moth, Tinagma obscurofasciella, mine the leaves. Apparently the foliage of White Avens is not attractive to mammalian herbivores; it is not often grazed by White-Tailed Deer. The hooked achenes can cling to the fur of mammals, feathers of birds, and clothing of humans; by this means, they are distributed far and wide.
Photographic Location: The photographs were taken near a powerline clearance at Busey Woods in Urbana, Illinois, at a tallgrass prairie of Meadowbrook Park in the same city, and along a woodland border at Chief Shemauger Park in the same city.
Comments: The flowers of White Avens resemble those of various Rubus spp. (Blackberries), except that they are a little smaller. The structure of its flowers is typical of many species in the Rose family. This is probably the most common Geum sp. (Avens) in Illinois. In general, White Avens can be distinguished from other species of Avens by its bright white petals, which are as long or longer than the sepals. Its lower cauline leaves are trifoliate, whereas the lower cauline leaves of other species of Avens are often oddly pinnate with 5 or more leaflets. In particular, Geum laciniatum (Rough Avens) resembles White Avens and occurs in many of the same habitats. However, the petals of its flowers are shorter than the sepals. The flowering stalks of White Avens are finely pubescent, while the flowering stalks of Rough Avens have coarse spreading hairs. Another species, Avens virginianum (Pale Avens), is restricted to southern Illinois. The petals of its flowers are cream rather than bright white, and they are substantially shorter than the sepals. Unlike White Avens, its lower cauline leaves are often odd-pinnate with 5 leaflets.
The basal leaves are similar to the cauline leaves, except they are dark green and odd-pinnate with more than 3 leaflets. The wrinkled upper surface of each leaf is either hairless or it has scattered hairs that are very short and bristly; the lower surface is either hairless or it has a few hairs along the major veins. The lower leaves have stout petioles up to 1" long, while the upper leaves have either short petioles or they are sessile. At the base of each petiole, there are a pair of leafy stipules up to ½" long that are usually toothed along their margins. Each upper stem often terminates in an inflorescence of 1-3 flowers; sometimes individual flowers are produced from the axils of the upper leaves. The peduncles are up to 3" long and finely pubescent; they divide into shorter pedicels when there is more than one flower in the inflorescence.
Each flower is about ½" across, consisting of 5 bright white petals, 5 triangular green sepals, and numerous stamens surrounding a cluster of green carpels with elongated styles. The sepals are the same length or shorter than the petals; they are initially spreading, but curve downward with age. The anthers of the stamens are initially white, but they soon turn brown. The receptacle of each flower (the surface underneath the carpels) is pubescent. The blooming period occurs during the summer and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a spheroid cluster of achenes with persistent styles that are hooked at their tips. This fruiting cluster spans about ¾" across; it is initially green, but eventually turns brown. The root system consists of a taproot and rhizomes; from the latter, vegetative offsets can be produced. This plant occasionally forms loose colonies.
Cultivation: The preference is light shade or partial sun, moist to slightly dry conditions, and a loam or clay-loam soil. At favorable sites, this plant can spread aggressively and is somewhat weedy. White Avens is able to grow underneath Black Walnut trees (Juglans nigra) because of its tolerance to the phytotoxic chemicals that are released by the fallen leaves and roots of this tree.
Range & Habitat: The native White Avens is a common plant that occurs in every county of Illinois (see Distribution Map). Habitats include mesic deciduous woodlands, woodland borders, thickets, partially shaded seeps, fence rows with woody vegetation, powerline clearances in wooded areas, and edges of yards. Sometimes White Avens can be found in disturbed meadows and tall-grass prairies, but this is less typical. It adapts well to disturbed areas.
Faunal Associations: The flowers attract various insects, including bees, wasps, flies, and beetles. These insects suck nectar; some bees also collect pollen, while Syrphid flies often feed on the pollen. Insects that feed on the foliage of White Avens and other Aven species (Geum spp.) consist primarily of aphids, including Acyrthosiphon pseudodirhodum, Amphorophora rossi (White Avens is the preferred host plant), Macrosiphum gei, Macrosiphum pallidum, and Macrosiphon pseudorosae. In addition, the larvae of a moth, Tinagma obscurofasciella, mine the leaves. Apparently the foliage of White Avens is not attractive to mammalian herbivores; it is not often grazed by White-Tailed Deer. The hooked achenes can cling to the fur of mammals, feathers of birds, and clothing of humans; by this means, they are distributed far and wide.
Photographic Location: The photographs were taken near a powerline clearance at Busey Woods in Urbana, Illinois, at a tallgrass prairie of Meadowbrook Park in the same city, and along a woodland border at Chief Shemauger Park in the same city.
Comments: The flowers of White Avens resemble those of various Rubus spp. (Blackberries), except that they are a little smaller. The structure of its flowers is typical of many species in the Rose family. This is probably the most common Geum sp. (Avens) in Illinois. In general, White Avens can be distinguished from other species of Avens by its bright white petals, which are as long or longer than the sepals. Its lower cauline leaves are trifoliate, whereas the lower cauline leaves of other species of Avens are often oddly pinnate with 5 or more leaflets. In particular, Geum laciniatum (Rough Avens) resembles White Avens and occurs in many of the same habitats. However, the petals of its flowers are shorter than the sepals. The flowering stalks of White Avens are finely pubescent, while the flowering stalks of Rough Avens have coarse spreading hairs. Another species, Avens virginianum (Pale Avens), is restricted to southern Illinois. The petals of its flowers are cream rather than bright white, and they are substantially shorter than the sepals. Unlike White Avens, its lower cauline leaves are often odd-pinnate with 5 leaflets.
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Miss Chen
2018年03月23日
Wilting in plants occurs when dehydration causes the cells in the leaves and stems to lose water. This water pressure, called turgor pressure, creates rigidity in leaves and stems. With loss of turgor pressure, the plant is unable to support itself. Leaves wilt and then become dry and die.
It is normal for cucumbers (Cucumis sativus) to wilt in the afternoon during hot weather, but wilting in the morning, dry foliage or dying leaves suggest a potential problem. Abnormal wilting in these annual vegetables can have several causes.
Growing Conditions
Before considering pests and diseases that cause cucumbers to wilt, assess the growing conditions of your plants to evaluate what might be causing your cucumbers to lose water.
Water
Cucumbers have a shallow root system and require 1 to 1 1/2 inches of water per week. Plants can wilt and dry out during periods of low to no rainfall. Rather than watering lightly every day, cucumbers should receive a single watering to 6 inches deep every five to seven days. Using mulch also helps to keep the soil around your plants moist.
Somewhat counterintuitively, overwatering can cause similar symptoms to dehydration. Too much water damages the plant's roots and affects its intake of oxygen and nutrients. Cucumbers that receive too much water can wilt and die, just like plants that don't receive enough.
Soil
Cucumbers need well-draining soil. Heavy clay soil or soil low on organic matter that drains poorly can cause too much water to collect around the roots of plants, causing them to wilt and die.
Correcting a soil drainage problem midseason can be difficult. Adding compost or mulch around your plants can begin to provide the organic material needed to amend the soil in the long term.
For future plantings, add 3 to 4 inches of organic matter such as compost or rotted manure for every 6 inches of clay soil. For every 6 inches of sandy or loam soil, add 1 to 2 inches of organic matter. Mix these amendments into the soil before planting your cucumbers. Planting cucumbers on mounds also helps to drain excess moisture away from plant roots.
Temperature
During cool, wet weather -- air temperatures below 50 degrees Fahrenheit or soil temperatures below 62 F -- cucumber plants may become yellow and wilted, and the edges of the leaves may turn brown. Floating row covers -- light fabric sheets that can cover an entire row of plants -- can raise temperatures several degrees around the plant and help cold-sensitive plants like cucumbers to withstand cold snaps. Once the cool spell passes, cucumbers must be uncovered to allow pollinating insects access to the flowers. Otherwise, your plants will not produce fruit.
Pests
Pest damage to the vines and stems of cucumber plants can prevent water from reaching the leaves and cause plants to wilt.
Squash Bugs
Squash bugs can affect all cucurbit plants, including cucumbers. Adults are elongated, shield-shaped insects about an inch long, but you will generally notice the immature nymphs or eggs on your plants first. Nymphs have pale green or bluish gray bodies with dark-colored legs, and they typically cluster together. Squash bugs generally lay their eggs on the undersides of the leaves in the fork where leaf veins meet. Eggs are copper-colored and are generally laid in orderly rows.
Squash bugs feed on the stems of cucumber plants, draining the plant of water and nutrients and causing the leaves to wilt. You may also observe yellow spots or leaves browning and dying on the plant. Mature plants can withstand mild infestations, but serious infestations or infestations on young plants can kill your cucumbers.
Begin monitoring your garden in early June for squash bug activity, as the eggs and nymphs are easier to spot and destroy than the adults. Insecticides are rarely required for squash bug infestations. Instead, inspect plants every few days and drown nymphs and adults in a jar of warm, soapy water. Crush any eggs that you find. You can trap squash bugs by placing boards in your garden overnight. Adult squash bugs will hide under the boards and can be collected and destroyed in the morning.
Remove weeds and dead plant material from the area around your cucumbers to eliminate hiding places for squash bugs. At the end of the season, remove old cucumber vines to minimize sites for squash bugs to overwinter.
Squash Vine Borers
Cucumbers can also be afflicted by the squash vine borer, although this pest generally prefers squash and pumpkins. Adult insects -- wasp-like moths distinguished by their gray wings and orange bodies -- lay their eggs at the base of cucumber vines. When the larvae emerge, they burrow into the vines to feed, disrupting the passage of water into the leaves, which can cause wilting. Leaves served by that vine will eventually die. You can diagnose a problem with squash vine borers by observing whether there are holes at the base of the vine; the hole is often surrounded by an orange or green sawdustlike material called frass.
Begin monitoring plants in late June for the presence of adult squash vine borers. You can place a yellow-colored pan filled with water near your plants; yellow attracts adult borers, and the moths will drown in the water. If you observe adults, cover your plants with floating row covers for two weeks.
Once borer larvae have burrowed into a vine, the pest cannot be controlled. Promptly remove any dead borer-infested vines from the garden, since after emerging from the vine, larvae will overwinter in the soil and could reinfest your plants the following year.
Diseases
Bacterial Wilt
Bacterial wilt is a disease spread to cucumbers by the cucumber beetle, a small yellow beetle with black stripes or spots. These beetles spread the disease from plant to plant as they feed. Leaves turn pale green and begin to wilt during the day, but they initially recover at night. Leaves then begin to turn yellow or brown around the edges, and wilting becomes more severe and begins to progress down the vine. Cucumbers wilt and die quickly after infection begins.
There is no treatment for bacterial wilt. Remove and bury infected plants as quickly as possible to prevent the disease from spreading to other plants.
Phytophthora Blight
Phytophthora blight can cause wilting leaves in cucumbers, although this disease tends to affect squash and pumpkin more often. The disease is caused by a fungus that grows best in warm weather following heavy rains or very wet conditions. In addition to wilting leaves, affected plants show yellow leaves and rotten spots on the leaves, vines and fruit. Phytophthora blight can spread quickly and kill an entire cucumber crop.
Fungicides are not very effective against Phytophthora blight, and the best strategies against the disease are preventative. Remove any infected vines and fruit immediately from your garden and bury them. Do not compost them or leave them near your garden, as spores can spread. Choose a well-draining site for growing cucumbers, control weeds in the area, do not work in the garden during wet conditions and water your cucumbers at the base of the plant rather than overhead.
Fusarium Wilt
Fusarium wilt, which is caused by a fungus, often appears first as wilting during the day followed by recovery at night. Growth may be stunted, leaves may yellow and show rotted lesions and a pink fungus may grow on vines. Fusarium wilt cannot be treated, and because the fungus can endure in the soil for years, future crops in the area may continue to be affected. In areas affected by Fusarium wilt, you should plant only wilt-resistant cultivars.
It is normal for cucumbers (Cucumis sativus) to wilt in the afternoon during hot weather, but wilting in the morning, dry foliage or dying leaves suggest a potential problem. Abnormal wilting in these annual vegetables can have several causes.
Growing Conditions
Before considering pests and diseases that cause cucumbers to wilt, assess the growing conditions of your plants to evaluate what might be causing your cucumbers to lose water.
Water
Cucumbers have a shallow root system and require 1 to 1 1/2 inches of water per week. Plants can wilt and dry out during periods of low to no rainfall. Rather than watering lightly every day, cucumbers should receive a single watering to 6 inches deep every five to seven days. Using mulch also helps to keep the soil around your plants moist.
Somewhat counterintuitively, overwatering can cause similar symptoms to dehydration. Too much water damages the plant's roots and affects its intake of oxygen and nutrients. Cucumbers that receive too much water can wilt and die, just like plants that don't receive enough.
Soil
Cucumbers need well-draining soil. Heavy clay soil or soil low on organic matter that drains poorly can cause too much water to collect around the roots of plants, causing them to wilt and die.
Correcting a soil drainage problem midseason can be difficult. Adding compost or mulch around your plants can begin to provide the organic material needed to amend the soil in the long term.
For future plantings, add 3 to 4 inches of organic matter such as compost or rotted manure for every 6 inches of clay soil. For every 6 inches of sandy or loam soil, add 1 to 2 inches of organic matter. Mix these amendments into the soil before planting your cucumbers. Planting cucumbers on mounds also helps to drain excess moisture away from plant roots.
Temperature
During cool, wet weather -- air temperatures below 50 degrees Fahrenheit or soil temperatures below 62 F -- cucumber plants may become yellow and wilted, and the edges of the leaves may turn brown. Floating row covers -- light fabric sheets that can cover an entire row of plants -- can raise temperatures several degrees around the plant and help cold-sensitive plants like cucumbers to withstand cold snaps. Once the cool spell passes, cucumbers must be uncovered to allow pollinating insects access to the flowers. Otherwise, your plants will not produce fruit.
Pests
Pest damage to the vines and stems of cucumber plants can prevent water from reaching the leaves and cause plants to wilt.
Squash Bugs
Squash bugs can affect all cucurbit plants, including cucumbers. Adults are elongated, shield-shaped insects about an inch long, but you will generally notice the immature nymphs or eggs on your plants first. Nymphs have pale green or bluish gray bodies with dark-colored legs, and they typically cluster together. Squash bugs generally lay their eggs on the undersides of the leaves in the fork where leaf veins meet. Eggs are copper-colored and are generally laid in orderly rows.
Squash bugs feed on the stems of cucumber plants, draining the plant of water and nutrients and causing the leaves to wilt. You may also observe yellow spots or leaves browning and dying on the plant. Mature plants can withstand mild infestations, but serious infestations or infestations on young plants can kill your cucumbers.
Begin monitoring your garden in early June for squash bug activity, as the eggs and nymphs are easier to spot and destroy than the adults. Insecticides are rarely required for squash bug infestations. Instead, inspect plants every few days and drown nymphs and adults in a jar of warm, soapy water. Crush any eggs that you find. You can trap squash bugs by placing boards in your garden overnight. Adult squash bugs will hide under the boards and can be collected and destroyed in the morning.
Remove weeds and dead plant material from the area around your cucumbers to eliminate hiding places for squash bugs. At the end of the season, remove old cucumber vines to minimize sites for squash bugs to overwinter.
Squash Vine Borers
Cucumbers can also be afflicted by the squash vine borer, although this pest generally prefers squash and pumpkins. Adult insects -- wasp-like moths distinguished by their gray wings and orange bodies -- lay their eggs at the base of cucumber vines. When the larvae emerge, they burrow into the vines to feed, disrupting the passage of water into the leaves, which can cause wilting. Leaves served by that vine will eventually die. You can diagnose a problem with squash vine borers by observing whether there are holes at the base of the vine; the hole is often surrounded by an orange or green sawdustlike material called frass.
Begin monitoring plants in late June for the presence of adult squash vine borers. You can place a yellow-colored pan filled with water near your plants; yellow attracts adult borers, and the moths will drown in the water. If you observe adults, cover your plants with floating row covers for two weeks.
Once borer larvae have burrowed into a vine, the pest cannot be controlled. Promptly remove any dead borer-infested vines from the garden, since after emerging from the vine, larvae will overwinter in the soil and could reinfest your plants the following year.
Diseases
Bacterial Wilt
Bacterial wilt is a disease spread to cucumbers by the cucumber beetle, a small yellow beetle with black stripes or spots. These beetles spread the disease from plant to plant as they feed. Leaves turn pale green and begin to wilt during the day, but they initially recover at night. Leaves then begin to turn yellow or brown around the edges, and wilting becomes more severe and begins to progress down the vine. Cucumbers wilt and die quickly after infection begins.
There is no treatment for bacterial wilt. Remove and bury infected plants as quickly as possible to prevent the disease from spreading to other plants.
Phytophthora Blight
Phytophthora blight can cause wilting leaves in cucumbers, although this disease tends to affect squash and pumpkin more often. The disease is caused by a fungus that grows best in warm weather following heavy rains or very wet conditions. In addition to wilting leaves, affected plants show yellow leaves and rotten spots on the leaves, vines and fruit. Phytophthora blight can spread quickly and kill an entire cucumber crop.
Fungicides are not very effective against Phytophthora blight, and the best strategies against the disease are preventative. Remove any infected vines and fruit immediately from your garden and bury them. Do not compost them or leave them near your garden, as spores can spread. Choose a well-draining site for growing cucumbers, control weeds in the area, do not work in the garden during wet conditions and water your cucumbers at the base of the plant rather than overhead.
Fusarium Wilt
Fusarium wilt, which is caused by a fungus, often appears first as wilting during the day followed by recovery at night. Growth may be stunted, leaves may yellow and show rotted lesions and a pink fungus may grow on vines. Fusarium wilt cannot be treated, and because the fungus can endure in the soil for years, future crops in the area may continue to be affected. In areas affected by Fusarium wilt, you should plant only wilt-resistant cultivars.
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Miss Chen
2018年03月19日
Description: This annual or biennial wildflower develops ascending to sprawling stems about 1½–3' long. The stems are light green to reddish green and pubescent with short spreading hairs. Either opposite or alternate leaves occur at intervals along the stems; the leaf blades are up to 3" long and 3" across and deeply cleft into 3-5 palmate lobes. The leaf margins are sparingly dentate or further divided into small secondary lobes. The upper leaf surfaces are medium green and hairless (or sparingly so), while the their lower surfaces are pale green and pubescent. The petioles are light green and pubescent. At the base of each petiole, there is a pair of small linear stipules. From the axils of the middle to upper leaves, clusters of 2 or more flowers develop on slender pubescent stalks; these stalks are about ¾–1½" long at maturity.
Each flower is about 1/3" (8 mm.) across, consisting of 5 light pink petals, 5 green sepals, 10 stamens, and a pistil. Fine pink lines radiate from the throat of each flower. The petals are oblong in shape and slightly notched at their tips. The sepals are lanceolate to ovate and pubescent; each sepal has an awn-like tip about 1.5 mm. long. The blooming period occurs during the summer and lasts about 2 months. Usually, only a few flowers are in bloom at the same time. Each flower is replaced by a narrow columnar fruit about ½–¾" long that tapers to a short beak. At maturity, the fruit splits open into 5 slender sections from the bottom, remaining connected together at the apex. By this process, the seeds are mechanically ejected from the mother plant.
Cultivation: The preference is partial sun, mesic to dry-mesic conditions, and cool to warm summer temperatures. Different kinds of soil are tolerated, including those that are sandy or rocky.
Range & Habitat: Northern Cranesbill is restricted to NE Illinois, where it is rare and native to the area (see Distribution Map). This species is state-listed as 'endangered.' Illinois lies at the southern range-limit of this boreal wildflower. Habitats include woodland openings, sandy Black Oak woodlands, typical and sandy savannas, and rocky outcrops. This wildflower becomes more abundant after a wildfire; there is some evidence that its seeds germinate in response to heat and/or light.
Faunal Associations: The flowers are pollinated by small flies (particularly Syrphid flies) and small bees (particularly Halictid bees). Both nectar and pollen are available as floral rewards to such visitors. One insect that sucks on the juices of Geranium spp. is Macrosiphum geranii (Geranium Aphid). The seeds of some Geranium spp. are eaten by such birds as the Mourning Dove and Bobwhite Quail to a limited extent.
Photographic Location: A nature preserve in Cook County, Illinois. The photographs were taken by Lisa Culp (Copyright © 2009).
Comments: This is one of several annual or biennial Geraniums (Geranium spp.) in Illinois. The majority of these species have been introduced from Eurasia, although some of them are native. All of these species have relatively small flowers, palmately cleft simple leaves (see exception below), and a sprawling to ascending habit. As a result, they can be difficult to distinguish from each other. Northern Cranesbill can be identified through the following combination of characteristics: 1) It produces small flowers (about 1/3" across) in clusters of 2 or more, 2) the stems and stalks of the flowers are pubescent with short spreading hairs, 3) the pedicels of the flowers/fruits are longer than the sepals, and 4) the sepals have awn-like tips. One aberrant species in this group, Herb Robert (Geranium robertianum), differs from the others by its leaves, which are palmately divided into leaflets with petioles.
Each flower is about 1/3" (8 mm.) across, consisting of 5 light pink petals, 5 green sepals, 10 stamens, and a pistil. Fine pink lines radiate from the throat of each flower. The petals are oblong in shape and slightly notched at their tips. The sepals are lanceolate to ovate and pubescent; each sepal has an awn-like tip about 1.5 mm. long. The blooming period occurs during the summer and lasts about 2 months. Usually, only a few flowers are in bloom at the same time. Each flower is replaced by a narrow columnar fruit about ½–¾" long that tapers to a short beak. At maturity, the fruit splits open into 5 slender sections from the bottom, remaining connected together at the apex. By this process, the seeds are mechanically ejected from the mother plant.
Cultivation: The preference is partial sun, mesic to dry-mesic conditions, and cool to warm summer temperatures. Different kinds of soil are tolerated, including those that are sandy or rocky.
Range & Habitat: Northern Cranesbill is restricted to NE Illinois, where it is rare and native to the area (see Distribution Map). This species is state-listed as 'endangered.' Illinois lies at the southern range-limit of this boreal wildflower. Habitats include woodland openings, sandy Black Oak woodlands, typical and sandy savannas, and rocky outcrops. This wildflower becomes more abundant after a wildfire; there is some evidence that its seeds germinate in response to heat and/or light.
Faunal Associations: The flowers are pollinated by small flies (particularly Syrphid flies) and small bees (particularly Halictid bees). Both nectar and pollen are available as floral rewards to such visitors. One insect that sucks on the juices of Geranium spp. is Macrosiphum geranii (Geranium Aphid). The seeds of some Geranium spp. are eaten by such birds as the Mourning Dove and Bobwhite Quail to a limited extent.
Photographic Location: A nature preserve in Cook County, Illinois. The photographs were taken by Lisa Culp (Copyright © 2009).
Comments: This is one of several annual or biennial Geraniums (Geranium spp.) in Illinois. The majority of these species have been introduced from Eurasia, although some of them are native. All of these species have relatively small flowers, palmately cleft simple leaves (see exception below), and a sprawling to ascending habit. As a result, they can be difficult to distinguish from each other. Northern Cranesbill can be identified through the following combination of characteristics: 1) It produces small flowers (about 1/3" across) in clusters of 2 or more, 2) the stems and stalks of the flowers are pubescent with short spreading hairs, 3) the pedicels of the flowers/fruits are longer than the sepals, and 4) the sepals have awn-like tips. One aberrant species in this group, Herb Robert (Geranium robertianum), differs from the others by its leaves, which are palmately divided into leaflets with petioles.
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Miss Chen
2018年03月19日
Description: This wildflower is an annual or biennial about ½–2' tall. Small plants are unbranched or sparingly branched, while large plants form frequent lateral stems in the upper leaf axils. The stems are light green to reddish purple, 4-angular, and slightly winged; the central stem is erect, while the lateral stems curve upward. Pairs of opposite leaves occur along each stem, each pair rotating about 90° from the pair of leaves immediately below. The leaves are up to 2½" long and about half as much across, becoming slightly smaller as they ascend the stems. The leaves are ovate-cordate to ovate, sessile or slightly clasping at their bases, and smooth along their margins. Their upper surfaces are yellowish green, green, or tinted slightly purple; each leaf has 3-5 parallel veins. Both the stems and leaves are hairless.
The central stem and upper lateral stems (if present) terminate in clusters of 3-7 flowers on short pedicels. Frequently, there are additional clusters of 1-5 flowers from the axils of the upper leaves. All of these flowers are held stiffly erect. Each flower is about ¾" long and ¼" across; it has a long tubular corolla and a short green calyx with 5 slender teeth. The apex of each corolla has 5 triangular lobes that fold together to form a point; the corolla is closed or nearly so. There are no interconnecting fringes to join these lobes. The corollas are blue-violet, purple, or nearly white; they have fine purple veins along their sides. Inside each corolla, there are five stamens and a pistil. The erect lobes of the calyx are narrowly oblong-lanceolate in shape. Underneath the clustered flowers, the leaves are reduced to leafy bracts. The blooming period occur from late summer to mid-fall and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a seed capsule that dividesDistribution Map into 2 parts to release the numerous tiny seeds. These seeds are distributed by wind and water. The root system consists of a taproot. This wildflower reproduces by reseeding itself; it does not spread vegetatively.
Cultivation: The preference is full sun to light shade, moist to dry conditions, and a somewhat barren soil containing clay or rocky material. Competition from taller plants should be restricted. The size of individual plants and the abundance of their flowers can vary considerably depending on the availability of moisture and nutrients.
Range & Habitat: The native Stiff Gentian is occasional in the northern half of Illinois, while in the southern half of the state it is rare or absent. Populations of this species may be declining. Habitats include hill prairies, upland savannas, thinly wooded slopes, rocky meadows, banks of streams in wooded areas, calcareous seeps, and edges of cliffs. This species is usually found in high quality natural habitats, often where limestone is close to the ground surface.
Faunal Associations: So far, information about floral-faunal relationships for this species has not been encountered. The long tubular shape of the closed corollas suggests that long-tongued bees cross-pollinate the flowers.
Photographic Location: The edge of a partially shaded cliff at the Pine Hills Nature Preserve in west-central Indiana.
Comments: Like several other gentian species, the flowers of Stiff Gentian provide attractive blue-violet color during the fall; this is one of the last species to remain in bloom. Stiff Gentian in Illinois consists of var. occidentalis; the typical variety is found east of Ohio. Stiff Gentian is easily distinguished by its peculiar flowers, which are shorter (1" long or less) and more narrow (¼" across) than the flowers of other gentians with closed corollas. Sometimes, Stiff Gentian is still referred to as Gentiana quinquefolia, but this genus has been reserved for the perennial gentians, of which there are several species still extant in Illinois.
The central stem and upper lateral stems (if present) terminate in clusters of 3-7 flowers on short pedicels. Frequently, there are additional clusters of 1-5 flowers from the axils of the upper leaves. All of these flowers are held stiffly erect. Each flower is about ¾" long and ¼" across; it has a long tubular corolla and a short green calyx with 5 slender teeth. The apex of each corolla has 5 triangular lobes that fold together to form a point; the corolla is closed or nearly so. There are no interconnecting fringes to join these lobes. The corollas are blue-violet, purple, or nearly white; they have fine purple veins along their sides. Inside each corolla, there are five stamens and a pistil. The erect lobes of the calyx are narrowly oblong-lanceolate in shape. Underneath the clustered flowers, the leaves are reduced to leafy bracts. The blooming period occur from late summer to mid-fall and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a seed capsule that dividesDistribution Map into 2 parts to release the numerous tiny seeds. These seeds are distributed by wind and water. The root system consists of a taproot. This wildflower reproduces by reseeding itself; it does not spread vegetatively.
Cultivation: The preference is full sun to light shade, moist to dry conditions, and a somewhat barren soil containing clay or rocky material. Competition from taller plants should be restricted. The size of individual plants and the abundance of their flowers can vary considerably depending on the availability of moisture and nutrients.
Range & Habitat: The native Stiff Gentian is occasional in the northern half of Illinois, while in the southern half of the state it is rare or absent. Populations of this species may be declining. Habitats include hill prairies, upland savannas, thinly wooded slopes, rocky meadows, banks of streams in wooded areas, calcareous seeps, and edges of cliffs. This species is usually found in high quality natural habitats, often where limestone is close to the ground surface.
Faunal Associations: So far, information about floral-faunal relationships for this species has not been encountered. The long tubular shape of the closed corollas suggests that long-tongued bees cross-pollinate the flowers.
Photographic Location: The edge of a partially shaded cliff at the Pine Hills Nature Preserve in west-central Indiana.
Comments: Like several other gentian species, the flowers of Stiff Gentian provide attractive blue-violet color during the fall; this is one of the last species to remain in bloom. Stiff Gentian in Illinois consists of var. occidentalis; the typical variety is found east of Ohio. Stiff Gentian is easily distinguished by its peculiar flowers, which are shorter (1" long or less) and more narrow (¼" across) than the flowers of other gentians with closed corollas. Sometimes, Stiff Gentian is still referred to as Gentiana quinquefolia, but this genus has been reserved for the perennial gentians, of which there are several species still extant in Illinois.
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Miss Chen
2018年03月19日
Description: This low deciduous shrub is 1-3' tall, branching occasionally. Young stems are yellowish green to reddish brown, pubescent or hairless, while older stems are light gray to nearly black. The wood of the stems is relatively brittle and weak. The blades of alternate leaves are 1-2¼" long and ½-1" across; they are oblong-ovate, obovate, or narrowly oval and smooth along their margins. The upper surface of the blades is yellowish green and slightly shiny, while the lower surface is dull yellowish green and more or less covered with fine resinous dots that are yellow (more visible with a 10x hand lens). The petiole is short and slender. Short fine hairs are often present on the lower blade surface and petioles. The flowers develop in raceme-like clusters from the axils of the leaves. Individual flowers are up to 1/3" (8 mm.) long and a little less across, consisting of a short yellowish green calyx with 5 broad lobes and a tubular corolla with 5 tiny lobes along its rim that are strongly recurved. The red corolla (rarely white) is slightly constricted toward its throat, forming an urn-like shape. Each flower also has 10 inserted stamens and a pistil with a single style. The pedicels and calyces of the flowers are covered with short fine hairs and/or yellow resinous dots. The blooming period occurs from late spring to early summer, lasting about 3 weeks. Later, the flowers are replaced by globoid berries up to 1/3" (8 mm.) across. These berries are initially green, but they become blue-black at maturity. The interior of each berry is fleshy and sweet; it contains 10 seeds, which are individually up to 2 mm. long. The woody root system is shallow and branching; it can develop clonal offsets from underground runners. Colonies of plants are often produced. The leaves turn red during the autumn before falling to the ground.
Cultivation: The preference is partial sun, mesic to dry conditions, and an acidic soil that is sandy or rocky. Plants that are grown in too much shade may fail to produce flowers and fruit. The flowers are self-fertile, but fruit production is better when there is cross-pollination.
Range & Habitat: Black Huckleberry is a native shrub that is found primarily in northern and southern Illinois (see Distribution Map), where it is occasional in sandy or rocky areas. Elsewhere in the state, it is rare or absent. Habitats consist of upland rocky woodlands, wooded slopes, sandy savannas, openings in sandy woodlands, sandy shrub prairies, rocky bluffs and sandstone cliffs, sandy or rocky thickets, and stabilized sand dunes. Outside of Illinois, this shrub is sometimes found in bogs. Because it is able to resprout from underground runners, this shrub adapts to fire-prone habitats. In sandy shrub prairies, it is occasionally the dominant plant.
Faunal Associations: The flowers are cross-pollinated primarily by honeybees, bumblebees, and Andrenid bees. Other floral visitors include the Karner Blue butterfly and various Syrphid flies. These insects seek primarily nectar from the flowers, although the Syrphid flies probably feed on the pollen. The caterpillars of the butterfly Callophrys henrici (Henry's Elfin) feed on Black Huckleberry, as do the caterpillars of several moths, specifically: Amorbia humerosana (White-Lined Leafroller), Chrysanympha formosa (Formosa Looper Moth), Croesia curvalana (Blueberry Leaftier), Cyclophora pendulinaria (Sweet Fern Geometer), Melanomma auricinctaria (Gold-Lined Melanomma), Pangrapta decoralis (Decorated Owlet), Psectraglaea carnosa (Pink Sallow), Sphinx gordius (Gordian Sphinx), Synchlora aerata (Wavy-Lined Emerald), and Zomaria interruptolineana (Broken-Lined Zomaria). Another insect that feeds on Black Huckleberry is Melanoplus fasciatus (Huckleberry Spur-Throated Grasshopper).
Among vertebrate animals, the fruit is eaten by many species of upland gamebirds and songbirds (see Bird Table). Mammals that eat the fruit include the Gray Fox, Red Fox, Raccoon, Opossum, Striped Skunk, Fox Squirrel, Gray Squirrel, Eastern Chipmunk, and White-Footed Mouse. Dense colonies of Black Huckleberry in shrub prairie provide nesting habitat for the Northern Harrier and probably other birds. Such colonies provide protective cover for small animals.
Photographic Location: The photo of the flowers was taken in a sandy savanna at the Oak Opening Nature Preserve in NW Ohio, while the photos of the leafy shrub, twig, and leaf underside were taken in an upland rocky woodland near a ravine at The Potholes in west-central Indiana.
Comments: The berries of huckleberries are very similar to the berries of blueberries, except the latter usually contain more seeds (8-20) that are smaller in size. The foliage and woody stems of Black Huckleberry are quite similar to those of low-bush blueberries (particularly Vaccinium pallidum), except the leaf undersides of the former shrub are covered with resinous yellow dots, while the leaf undersides of blueberries lack such resinous dots. In Illinois, Black Huckleberry is the only species in its genus, although other huckleberry species can be found in the southeastern United States.
Cultivation: The preference is partial sun, mesic to dry conditions, and an acidic soil that is sandy or rocky. Plants that are grown in too much shade may fail to produce flowers and fruit. The flowers are self-fertile, but fruit production is better when there is cross-pollination.
Range & Habitat: Black Huckleberry is a native shrub that is found primarily in northern and southern Illinois (see Distribution Map), where it is occasional in sandy or rocky areas. Elsewhere in the state, it is rare or absent. Habitats consist of upland rocky woodlands, wooded slopes, sandy savannas, openings in sandy woodlands, sandy shrub prairies, rocky bluffs and sandstone cliffs, sandy or rocky thickets, and stabilized sand dunes. Outside of Illinois, this shrub is sometimes found in bogs. Because it is able to resprout from underground runners, this shrub adapts to fire-prone habitats. In sandy shrub prairies, it is occasionally the dominant plant.
Faunal Associations: The flowers are cross-pollinated primarily by honeybees, bumblebees, and Andrenid bees. Other floral visitors include the Karner Blue butterfly and various Syrphid flies. These insects seek primarily nectar from the flowers, although the Syrphid flies probably feed on the pollen. The caterpillars of the butterfly Callophrys henrici (Henry's Elfin) feed on Black Huckleberry, as do the caterpillars of several moths, specifically: Amorbia humerosana (White-Lined Leafroller), Chrysanympha formosa (Formosa Looper Moth), Croesia curvalana (Blueberry Leaftier), Cyclophora pendulinaria (Sweet Fern Geometer), Melanomma auricinctaria (Gold-Lined Melanomma), Pangrapta decoralis (Decorated Owlet), Psectraglaea carnosa (Pink Sallow), Sphinx gordius (Gordian Sphinx), Synchlora aerata (Wavy-Lined Emerald), and Zomaria interruptolineana (Broken-Lined Zomaria). Another insect that feeds on Black Huckleberry is Melanoplus fasciatus (Huckleberry Spur-Throated Grasshopper).
Among vertebrate animals, the fruit is eaten by many species of upland gamebirds and songbirds (see Bird Table). Mammals that eat the fruit include the Gray Fox, Red Fox, Raccoon, Opossum, Striped Skunk, Fox Squirrel, Gray Squirrel, Eastern Chipmunk, and White-Footed Mouse. Dense colonies of Black Huckleberry in shrub prairie provide nesting habitat for the Northern Harrier and probably other birds. Such colonies provide protective cover for small animals.
Photographic Location: The photo of the flowers was taken in a sandy savanna at the Oak Opening Nature Preserve in NW Ohio, while the photos of the leafy shrub, twig, and leaf underside were taken in an upland rocky woodland near a ravine at The Potholes in west-central Indiana.
Comments: The berries of huckleberries are very similar to the berries of blueberries, except the latter usually contain more seeds (8-20) that are smaller in size. The foliage and woody stems of Black Huckleberry are quite similar to those of low-bush blueberries (particularly Vaccinium pallidum), except the leaf undersides of the former shrub are covered with resinous yellow dots, while the leaf undersides of blueberries lack such resinous dots. In Illinois, Black Huckleberry is the only species in its genus, although other huckleberry species can be found in the southeastern United States.
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Miss Chen
2018年03月18日
Description: This herbaceous perennial plant is a twining vine up to 20' long that can climb adjacent vegetation and fences, otherwise it sprawls across the ground. The slender stems are light green to bright red and round, angular, or slightly ridged. They are largely hairless, except for minute stiff hairs along the ridges. At the base of the petioles, the stems are slightly swollen and have short ocreae (membranous sheaths) that are without bristles. The alternate leaves are up to 4" long and 2" across (excluding the petioles). They are cordate or ovate, smooth along the margins, hairless, and indented at the base. Their slender petioles are up to 1½" long and similar in appearance to the stems. The lower leaves have long petioles, while the smaller upper leaves are nearly sessile. From the axils of the leaves, there develops one or more racemes of flowers about 2-8" long. These racemes are usually more or less erect (although sometimes horizontal) and their central stalks are often terete with numerous fine ridges. The greenish white flowers occur in loose whorls along these racemes. They are initially semi-erect while in bloom, but dangle downward from their slender pedicels while developing their fruits. Each flower is about 1/6" (4 mm.) long, consisting of 5 greenish white tepals, 8 stamens, and an ovary with a tripartite style. The 3 outer tepals are conspicuously winged. The wings of these tepals can be smooth, undulate, or slightly jagged. The blooming period occurs from mid-summer to early fall and lasts about 1-2 months. Each flower is replaced by a winged fruit about 1/3" (8 mm.) long that consists of the 3 outer tepals enclosing a single achene. This fruit is initially greenish white like the flower, but it eventually becomes brown. The 3-angled achenes are about 1/8" (3 mm.) in length (or slightly longer). They are dark brown or black and shiny. The mature fruits can float on water or be blown about by the wind, thereby distributing the achenes. This plant reproduces by reseeding itself and can form sizable colonies at favorable sites.
Cultivation: The preference is partial sun, moist to mesic conditions, and a fertile loamy soil, although full sun, drier conditions, and rocky or gravelly soil are also tolerated. This vine develops rapidly during the summer and can smother small shrubs. It is quite aggressive.
Range & Habitat: The native Climbing Buckwheat is a common plant that occurs in every county of Illinois (see Distribution Map; the distribution of each variety for this species has been combined). Habitats include open woodlands in floodplain areas, woodland borders, thickets, riverbanks, ditches, sloping ground along bridges, and fence rows. This species is often found in moist areas along the edges of woodlands or near sources of water. It is thrives on disturbance and is rather weedy, although regular mowing and cultivation of the soil isn't tolerated because of its perennial habit.
Faunal Associations: The nectar of the flowers primarily attracts short-tongued bees, wasps, and flies. Some of the bees may also collect pollen. Less common visitors include butterflies, skippers, and beetles. The caterpillars of the moth Timandra amaturaria (Cross-Lined Wave) feed on Fallopia spp. (Climbing Buckwheats), as does the aphid, Macrosiphum venaefuscae. It seems likely that many of the insects that feed on Persicaria spp. (Smartweeds) and Polygonum spp. (Knotweeds) also feed on Climbing Buckwheats. The large seeds are an important source of food to many birds, especially upland gamebirds (see Bird Table). The White-Footed Mouse and other small mammals also eat the seeds. The foliage isn't usually eaten by mammalian herbivores, although cattle and other livestock may browse on it. The dense foliage provides cover for small mammals and nesting bird.
Photographic Location: Along a bridge in Urbana, Illinois.
Comments: This is a luxuriant vine that can smother everything in its path. However, the flowers and fruits are produced in abundance and are rather showy. There is a lack of consensus regarding the taxonomy of this variable species. Some botanists (the 'splitters') divide Fallopia scandens (Climbing Buckwheat) into 2 or 3 species, while others (the 'lumpers') recognize only a single species with different varieties. Similar to Yatskievych (2000), I prefer the taxonomy of the latter and regard Fallopia cristata (Crested Climbing Buckwheat) as a variety of Climbing Buckwheat, or Fallopia scandens cristata, as specimen plants tend to intergrade. However, according to Mohlenbrock (2002), Climbing Buckwheat has winged fruits that exceed 10 mm. in length, while the winged fruits of Crested Buckwheat are shorter. An older scientific name of Climbing Buckwheat is Polygonum scandens, while Crested Climbing Buckwheat has been referred to as Polygonum cristatum and Polygonum scandens cristatum. Another species in this genus, Fallopia convolvulus (Black Bindweed), is an adventive annual vine from Europe that is up to 6' long. The flowers and fruits of Black Bindweed are keeled, rather than conspicuously winged, and the sides of its 3-angled achenes are dull, rather than shiny.
Cultivation: The preference is partial sun, moist to mesic conditions, and a fertile loamy soil, although full sun, drier conditions, and rocky or gravelly soil are also tolerated. This vine develops rapidly during the summer and can smother small shrubs. It is quite aggressive.
Range & Habitat: The native Climbing Buckwheat is a common plant that occurs in every county of Illinois (see Distribution Map; the distribution of each variety for this species has been combined). Habitats include open woodlands in floodplain areas, woodland borders, thickets, riverbanks, ditches, sloping ground along bridges, and fence rows. This species is often found in moist areas along the edges of woodlands or near sources of water. It is thrives on disturbance and is rather weedy, although regular mowing and cultivation of the soil isn't tolerated because of its perennial habit.
Faunal Associations: The nectar of the flowers primarily attracts short-tongued bees, wasps, and flies. Some of the bees may also collect pollen. Less common visitors include butterflies, skippers, and beetles. The caterpillars of the moth Timandra amaturaria (Cross-Lined Wave) feed on Fallopia spp. (Climbing Buckwheats), as does the aphid, Macrosiphum venaefuscae. It seems likely that many of the insects that feed on Persicaria spp. (Smartweeds) and Polygonum spp. (Knotweeds) also feed on Climbing Buckwheats. The large seeds are an important source of food to many birds, especially upland gamebirds (see Bird Table). The White-Footed Mouse and other small mammals also eat the seeds. The foliage isn't usually eaten by mammalian herbivores, although cattle and other livestock may browse on it. The dense foliage provides cover for small mammals and nesting bird.
Photographic Location: Along a bridge in Urbana, Illinois.
Comments: This is a luxuriant vine that can smother everything in its path. However, the flowers and fruits are produced in abundance and are rather showy. There is a lack of consensus regarding the taxonomy of this variable species. Some botanists (the 'splitters') divide Fallopia scandens (Climbing Buckwheat) into 2 or 3 species, while others (the 'lumpers') recognize only a single species with different varieties. Similar to Yatskievych (2000), I prefer the taxonomy of the latter and regard Fallopia cristata (Crested Climbing Buckwheat) as a variety of Climbing Buckwheat, or Fallopia scandens cristata, as specimen plants tend to intergrade. However, according to Mohlenbrock (2002), Climbing Buckwheat has winged fruits that exceed 10 mm. in length, while the winged fruits of Crested Buckwheat are shorter. An older scientific name of Climbing Buckwheat is Polygonum scandens, while Crested Climbing Buckwheat has been referred to as Polygonum cristatum and Polygonum scandens cristatum. Another species in this genus, Fallopia convolvulus (Black Bindweed), is an adventive annual vine from Europe that is up to 6' long. The flowers and fruits of Black Bindweed are keeled, rather than conspicuously winged, and the sides of its 3-angled achenes are dull, rather than shiny.
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Miss Chen
2018年03月18日
Description: This is a herbaceous vine about 5-30' long that branches occasionally. Its slender stems have the capacity to twine around adjacent vegetation and fences, climbing upward and outward. The glabrous stems are light green, pale yellow, reddish green, or dark red. The stems are usually terete; less often, they are bluntly angular or narrowly ridged. Whorled and/or opposite leaves sometimes occur near the base of the vine, otherwise the leaves are alternate. At maturity, individual leaf blades are 2-4" long and 1½-3" across; they are narrowly cordate to cordate, smooth along their margins, and palmately veined (7-11 veins per leaf). The upper blade surface is medium green and glabrous, while the lower surface is pale green and sparsely short-pubescent (less often, glabrous or densely short-pubescent). Very young leaf blades are golden green in appearance. The slender petioles are 1½-6" long, light green to dark red, and glabrous or nearly so; sometimes there are tufts of hair where the petioles join the leaf blades. The leaf blades tend to hang downward from their petioles.
Wild Yam is dioecious, producing vines with either all male flowers or all female flowers. On male vines, panicles of numerous male flowers about 4-12" long develop from the leaf axils. Male flowers are arranged in small clusters of 1-3 along the branches of each panicle. Individual male flowers are about 1/8" (3 mm.) across, consisting of 6 whitish green or yellowish green tepals and 6 fertile stamens. On female vines, racemes of 5-15 female flowers about 3-9" long develop from the leaf axils. Individual female flowers are about 1/8" (3 mm.) across and 1/3" (8 mm.) long, consisting of 6 whitish green or yellowish green tepals and a large inferior ovary with 6 infertile stamens. The blooming period occurs during early summer. The female flowers are replaced by 3-celled seed capsules that are ovoid in shape and about 1" long; these capsules are strongly 3-angled and become golden green as they mature. Each cell of the capsule usually contains 2 seeds (less often, only 1). The flattened seeds have broad membranous wings; they are distributed by the wind. The root system is rhizomatous.
Cultivation: The preference is partial to full sun, moist to mesic conditions, and soil consisting of loam or sandy loam. This vine can survive in light shade, but it is less likely to produce flowers and seed capsules. There are very few problems with insects and disease organisms.
Range & Habitat: The native Wild Yam is occasional to locally common in Illinois; it is found in every county (see Distribution Map). Habitats include thinly wooded bluffs, typical savannas and sandy savannas, woodland borders, typical thickets and sandy thickets, moist sand prairies, powerline and railroad clearances in wooded areas, and fence rows. Wild Yam is found in both high quality and degraded habitats; it benefits from occasional wildfires and other kinds of disturbance that reduce competition from overhead canopy trees.
Faunal Associations: There is very little information about floral-faunal relationships for this species. The foliage appears to be avoided as a food source by mammalian herbivores. Dense tangles of this vine can enhance nesting habitat for birds and provide cover for various animals.
Photographic Location: The photograph of leaf blades was taken along a fence row in Vermilion County, Illinois, while the photographs of the seed capsules and flowers were taken in moist sandy thickets of the Indiana Dunes National Lakeshore in NW Indiana.
Comments: Like the somewhat similar Greenbriers and Carrion Flowers (Smilax spp.), Wild Yam is a monocot, rather than a dicot. This vine is related to the tropical Yam that is found in grocery stores, but it does not produce edible tubers. Wild Yam can be readily distinguished from similar vines by the palmate venation of its leaves, its racemes or panicles of tiny flowers, and its conspicuous 3-angled seed capsules. In southern Illinois, there is the very similar Dioscorea quaternata (Whorled Wild Yam), which tends to have more whorled leaves than the common Wild Yam that is described here. There is disagreement among authorities regarding the taxonomic status of Whorled Wild Yam: While some authorities regard it as a distinct species (e.g., Mohlenbrock, 2003), other authorities consider it to be merely a variety of Wild Yam, and still others think it is unworthy of any taxonomic recognition.
Wild Yam is dioecious, producing vines with either all male flowers or all female flowers. On male vines, panicles of numerous male flowers about 4-12" long develop from the leaf axils. Male flowers are arranged in small clusters of 1-3 along the branches of each panicle. Individual male flowers are about 1/8" (3 mm.) across, consisting of 6 whitish green or yellowish green tepals and 6 fertile stamens. On female vines, racemes of 5-15 female flowers about 3-9" long develop from the leaf axils. Individual female flowers are about 1/8" (3 mm.) across and 1/3" (8 mm.) long, consisting of 6 whitish green or yellowish green tepals and a large inferior ovary with 6 infertile stamens. The blooming period occurs during early summer. The female flowers are replaced by 3-celled seed capsules that are ovoid in shape and about 1" long; these capsules are strongly 3-angled and become golden green as they mature. Each cell of the capsule usually contains 2 seeds (less often, only 1). The flattened seeds have broad membranous wings; they are distributed by the wind. The root system is rhizomatous.
Cultivation: The preference is partial to full sun, moist to mesic conditions, and soil consisting of loam or sandy loam. This vine can survive in light shade, but it is less likely to produce flowers and seed capsules. There are very few problems with insects and disease organisms.
Range & Habitat: The native Wild Yam is occasional to locally common in Illinois; it is found in every county (see Distribution Map). Habitats include thinly wooded bluffs, typical savannas and sandy savannas, woodland borders, typical thickets and sandy thickets, moist sand prairies, powerline and railroad clearances in wooded areas, and fence rows. Wild Yam is found in both high quality and degraded habitats; it benefits from occasional wildfires and other kinds of disturbance that reduce competition from overhead canopy trees.
Faunal Associations: There is very little information about floral-faunal relationships for this species. The foliage appears to be avoided as a food source by mammalian herbivores. Dense tangles of this vine can enhance nesting habitat for birds and provide cover for various animals.
Photographic Location: The photograph of leaf blades was taken along a fence row in Vermilion County, Illinois, while the photographs of the seed capsules and flowers were taken in moist sandy thickets of the Indiana Dunes National Lakeshore in NW Indiana.
Comments: Like the somewhat similar Greenbriers and Carrion Flowers (Smilax spp.), Wild Yam is a monocot, rather than a dicot. This vine is related to the tropical Yam that is found in grocery stores, but it does not produce edible tubers. Wild Yam can be readily distinguished from similar vines by the palmate venation of its leaves, its racemes or panicles of tiny flowers, and its conspicuous 3-angled seed capsules. In southern Illinois, there is the very similar Dioscorea quaternata (Whorled Wild Yam), which tends to have more whorled leaves than the common Wild Yam that is described here. There is disagreement among authorities regarding the taxonomic status of Whorled Wild Yam: While some authorities regard it as a distinct species (e.g., Mohlenbrock, 2003), other authorities consider it to be merely a variety of Wild Yam, and still others think it is unworthy of any taxonomic recognition.
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Miss Chen
2018年03月18日
Description: This perennial plant is about 2½–5' tall, branching occasionally and more or less erect. The stems are variably hairy, sometimes having hairs that occur in lines along their length. These hairs are white and either straight or somewhat curved, but not conspicuously hooked. The compound leaves alternate along the stems; they are trifoliate. The petioles of the compound leaves are about ½–1½" in length. At the base of each petiole is a pair of inconspicuous stipules that are deciduous and at least 5 times longer than they are wide. The leaflets are about 1½–3½" long and about half as much across. They are ovate-lanceolate or ovate and have smooth margins. The base of each leaflet is quite rounded. The upper surface of each leaflet is green or dark green, and nearly glabrous or finely pubescent. The lower surface is light green and faintly reticulate. There are usually fine hairs on the lower leaf surface, especially along the major veins, but the amount is variable.
The upper stems terminate in panicles of light pink to purplish pink flowers. The larger panicles can be 1-2' long and have spreading stems that produce numerous flowers. Each flower is about ¼" long. These flowers have a typical structure for members of the Bean family, consisting of a hood and projecting keel. Near the center of each flower is a patch of white that is surrounded by a thin line of purple. The blooming period can occur from mid-summer to early fall, and lasts about a month. There is no floral scent. Each fertilized flower is replaced by a flat loment (a type of seedpod) consisting of 2-5 rounded segments. These loments are about ¾–1½" long and covered with clinging hairs. The root system consists of a taproot and nodule-forming secondary roots. This plant spreads by reseeding itself.
Cultivation: The preference is partial sun and mesic to slightly dry conditions. This plant usually grows in soil that contains loam, clay-loam, or some kind of rocky material. It does not appear to be affected by powdery mildew to the same extent as Desmodium canadense (Showy Tick Trefoil). Nitrogen is added to the soil through the root nodules.
Range & Habitat: Perplexing Tick Trefoil occurs occasionally in the majority of counties in Illinois; this native plant is a little more common in the southern half of the state than in the northern half (see Distribution Map). The map doesn't distinguish between the distribution of Desmodium perplexum and Desmodium glabellum. Habitats include savannas, rocky upland forests, edges of wooded areas, thickets, and limestone glades.
Faunal Associations: Like other Desmodium spp., long-tongued bees are the primary pollinators of the flowers. Typical visitors include bumblebees, long-horned bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.). These insects collect pollen. The caterpillars of the skippers, Thorybes pylades (Northern Cloudywing) and Thorybes bathyllus (Southern Cloudywing), feed on the foliage. The seeds are eaten by some upland gamebirds and small rodents, including the Bobwhite, Wild Turkey, and White-footed Mouse. Mammalian herbivores eat Tick Trefoils readily, including deer, rabbits, groundhogs, and livestock. These mammals help to distribute the seeds as the loments readily cling to their fur. The loments also cling to the clothing of humans.
Photographic Location: The edge of a wooded area in Judge Webber Park, Urbana, Illinois.
Comments: This Tick Trefoil species can produce large panicles of small flowers that are rather showy. It is one of the Desmodium spp. that blooms later in the year than many others. Unfortunately, it has been re-classified by taxonomists on several occasions, which may be the reason for the 'perplexum' in its scientific name. In some older sources of information, this plant is referred to as Desmodium dillenii and Desmodium glabellum. However, Desmodium glabellum is now considered a separate species with an appearance that is quite similar to Perplexing Tick Trefoil, while Desmodium dillenii is considered a defunct classification. Presumably, Desmodium perplexum and Desmodium glabellum can be distinguished as follows: 1) the former species has a faint reticulated network of veins on the lower surface of the leaflets, while the latter has a strong reticulated network of veins, and 2) the former species has hairs on the stems and leaves that are straight or somewhat curved, while the latter has hooked hairs. Other distinguishing features for Perplexing Tick Trefoil include inconspicuous stipules that are very narrow and deciduous (i.e., they wither away quickly), and petioles of the compound leaves that are at least ½" in length.
The upper stems terminate in panicles of light pink to purplish pink flowers. The larger panicles can be 1-2' long and have spreading stems that produce numerous flowers. Each flower is about ¼" long. These flowers have a typical structure for members of the Bean family, consisting of a hood and projecting keel. Near the center of each flower is a patch of white that is surrounded by a thin line of purple. The blooming period can occur from mid-summer to early fall, and lasts about a month. There is no floral scent. Each fertilized flower is replaced by a flat loment (a type of seedpod) consisting of 2-5 rounded segments. These loments are about ¾–1½" long and covered with clinging hairs. The root system consists of a taproot and nodule-forming secondary roots. This plant spreads by reseeding itself.
Cultivation: The preference is partial sun and mesic to slightly dry conditions. This plant usually grows in soil that contains loam, clay-loam, or some kind of rocky material. It does not appear to be affected by powdery mildew to the same extent as Desmodium canadense (Showy Tick Trefoil). Nitrogen is added to the soil through the root nodules.
Range & Habitat: Perplexing Tick Trefoil occurs occasionally in the majority of counties in Illinois; this native plant is a little more common in the southern half of the state than in the northern half (see Distribution Map). The map doesn't distinguish between the distribution of Desmodium perplexum and Desmodium glabellum. Habitats include savannas, rocky upland forests, edges of wooded areas, thickets, and limestone glades.
Faunal Associations: Like other Desmodium spp., long-tongued bees are the primary pollinators of the flowers. Typical visitors include bumblebees, long-horned bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.). These insects collect pollen. The caterpillars of the skippers, Thorybes pylades (Northern Cloudywing) and Thorybes bathyllus (Southern Cloudywing), feed on the foliage. The seeds are eaten by some upland gamebirds and small rodents, including the Bobwhite, Wild Turkey, and White-footed Mouse. Mammalian herbivores eat Tick Trefoils readily, including deer, rabbits, groundhogs, and livestock. These mammals help to distribute the seeds as the loments readily cling to their fur. The loments also cling to the clothing of humans.
Photographic Location: The edge of a wooded area in Judge Webber Park, Urbana, Illinois.
Comments: This Tick Trefoil species can produce large panicles of small flowers that are rather showy. It is one of the Desmodium spp. that blooms later in the year than many others. Unfortunately, it has been re-classified by taxonomists on several occasions, which may be the reason for the 'perplexum' in its scientific name. In some older sources of information, this plant is referred to as Desmodium dillenii and Desmodium glabellum. However, Desmodium glabellum is now considered a separate species with an appearance that is quite similar to Perplexing Tick Trefoil, while Desmodium dillenii is considered a defunct classification. Presumably, Desmodium perplexum and Desmodium glabellum can be distinguished as follows: 1) the former species has a faint reticulated network of veins on the lower surface of the leaflets, while the latter has a strong reticulated network of veins, and 2) the former species has hairs on the stems and leaves that are straight or somewhat curved, while the latter has hooked hairs. Other distinguishing features for Perplexing Tick Trefoil include inconspicuous stipules that are very narrow and deciduous (i.e., they wither away quickly), and petioles of the compound leaves that are at least ½" in length.
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Miss Chen
2018年03月08日
Description: This perennial wildflower is 2–3½' tall, sometimes branching in the upper half. The stems are light green and usually hairless; however, some variants of this species have pubescent stems. Alternate compound leaves occur at intervals along the stems; they are trifoliate and their leaflets are extended horizontally in relation to the ground. Individual leaflets are up to 3½" long and ¾" across; they are 3-6 times as long as they are wide. Some variants of this species have more narrow leaflets than others. The terminal leaflet is the same length or a little longer than the lateral leaflets. The leaflets are elliptic to oblong in shape and smooth along their margins. Their upper surfaces are medium green and glabrous, while their lower surfaces are pale to medium green and covered with appressed white hairs. The petioles of the compound leaves are up to 2" long, light green, and mostly hairless. At the base of each petiole, there is a pair of tiny deciduous stipules that are linear-lanceolate; these stipules soon wither away. The petiolules (secondary petioles) of the lateral leaflets are very short (less than 1/8" or 3 mm.), while the petiolules of the terminal leaflets are longer (up to ½").
Flowers
The upper stems terminate in either racemes or narrow panicles of flowers. The branches of each inflorescence are light green and covered with hooked hairs. Individual flowers are ¼" long (or a little more), consisting of 5 petals, a short tubular calyx with teeth, an ovary with a single style, and several hidden stamens. The flowers have a typical pea-like structure, consisting of an upright banner and 2 lateral wings that enclose a central keel. The petals are pink to rosy pink; at the base of the upper petal (banner), there are 1-2 tiny patches of yellow. The green calyx is covered with hooked hairs. The slender petioles of the flowers are about ½" long; they are green to reddish purple and also covered with hooked hairs. The blooming period occurs from mid-summer to early fall and lasts about 1–1½ months. There is no noticeable floral scent. Fertile flowers are replaced by flat loments (a type of seedpod) that are about ½–1½" long. Each loment consists of 2-6 rounded segments, a short stipe, and sometimes a short beak. Each segment of a loment is more rounded along the bottom than along the top; it contains a single seed. The loments are covered with hooked hairs. The root system consists of an elongated caudex with fibrous roots. This wildflower spreads by reseeding itself.
Cultivation: The preference is partial sun, mesic to dry-mesic conditions, and sandy or rocky soil.
Range & Habitat: The native Panicled Tick Trefoil is occasional in all areas of Illinois, except the NW section, where it is rare or absent (see Distribution Map). Habitats consist of thinly wooded bluffs, rocky open woodlands, sandy open woodlands, sandy savannas and typical savannas, woodland edges, thickets, rocky glades, and partially shaded roadside embankments. This wildflower is a pioneer species that prefers some disturbance from wildfires, selective logging, and others causes.
Faunal Associations: Long-tongued bees collect pollen from the flowers; these relatively uncommon floral visitors include bumblebees (Bombus spp.), leaf-cutting bees (Megachile spp.), and long-horned bees (Melissodes spp.). Other insects feed on the leaves, flowers, and seeds of Desmodium spp. (Tick Trefoils). For example, the caterpillars of several skippers feed on the leaves: Achalarus lyciades (Hoary Edge), Epargyreus clarus (Silver-Spotted Skipper), Thorybes bathyllus (Southern Cloudywing), and Thorybes pylades (Northern Cloudywing). The caterpillars of the butterfly Everes comyntas (Eastern Tailed Blue) also feed on the foliage, while the caterpillars of the butterfly Strymon melinus (Gray Hairstreak) eat the flowers and developing seedpods. These insect feeders include many kinds of beetles, and some species of thrips, aphids, moth caterpillars, and stinkbugs (see Insect Table). The seeds are eaten by some upland gamebirds (Bobwhite Quail, Wild Turkey) and small rodents (White-Footed Mouse, Deer Mouse), while the foliage is readily eaten by White-Tailed Deer and other hoofed mammalian herbivores. The Cottontail Rabbit also consumes the foliage. The sticky seedpods (loments) cling to the fur of animals and the clothing of humans. As a result, the seeds are carried to new locations.
Photographic Location: A sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: Among different populations of Panicled Tick Trefoil, there is significant variation in the width of the leaflets and the hairiness of the stems and leaflets. Usually, this wildflower has fairly narrow leaflets, hairless to nearly hairless stems, and hairless upper surfaces on the leaflets. It can be distinguished from other species in this genus by considering the following key characteristics: 1) the narrow leaflets are 3-6 times longer than they are across, 2) the petioles of the trifoliate leaves are fairly long (up to 2"), 3) the deciduous stipules of the trifoliate leaves are small and insignificant, and 4) the leaflets are rather long (up to 3½"). Panicled Tick Trefoil is one of the more common species of this genus in Illinois.
Flowers
The upper stems terminate in either racemes or narrow panicles of flowers. The branches of each inflorescence are light green and covered with hooked hairs. Individual flowers are ¼" long (or a little more), consisting of 5 petals, a short tubular calyx with teeth, an ovary with a single style, and several hidden stamens. The flowers have a typical pea-like structure, consisting of an upright banner and 2 lateral wings that enclose a central keel. The petals are pink to rosy pink; at the base of the upper petal (banner), there are 1-2 tiny patches of yellow. The green calyx is covered with hooked hairs. The slender petioles of the flowers are about ½" long; they are green to reddish purple and also covered with hooked hairs. The blooming period occurs from mid-summer to early fall and lasts about 1–1½ months. There is no noticeable floral scent. Fertile flowers are replaced by flat loments (a type of seedpod) that are about ½–1½" long. Each loment consists of 2-6 rounded segments, a short stipe, and sometimes a short beak. Each segment of a loment is more rounded along the bottom than along the top; it contains a single seed. The loments are covered with hooked hairs. The root system consists of an elongated caudex with fibrous roots. This wildflower spreads by reseeding itself.
Cultivation: The preference is partial sun, mesic to dry-mesic conditions, and sandy or rocky soil.
Range & Habitat: The native Panicled Tick Trefoil is occasional in all areas of Illinois, except the NW section, where it is rare or absent (see Distribution Map). Habitats consist of thinly wooded bluffs, rocky open woodlands, sandy open woodlands, sandy savannas and typical savannas, woodland edges, thickets, rocky glades, and partially shaded roadside embankments. This wildflower is a pioneer species that prefers some disturbance from wildfires, selective logging, and others causes.
Faunal Associations: Long-tongued bees collect pollen from the flowers; these relatively uncommon floral visitors include bumblebees (Bombus spp.), leaf-cutting bees (Megachile spp.), and long-horned bees (Melissodes spp.). Other insects feed on the leaves, flowers, and seeds of Desmodium spp. (Tick Trefoils). For example, the caterpillars of several skippers feed on the leaves: Achalarus lyciades (Hoary Edge), Epargyreus clarus (Silver-Spotted Skipper), Thorybes bathyllus (Southern Cloudywing), and Thorybes pylades (Northern Cloudywing). The caterpillars of the butterfly Everes comyntas (Eastern Tailed Blue) also feed on the foliage, while the caterpillars of the butterfly Strymon melinus (Gray Hairstreak) eat the flowers and developing seedpods. These insect feeders include many kinds of beetles, and some species of thrips, aphids, moth caterpillars, and stinkbugs (see Insect Table). The seeds are eaten by some upland gamebirds (Bobwhite Quail, Wild Turkey) and small rodents (White-Footed Mouse, Deer Mouse), while the foliage is readily eaten by White-Tailed Deer and other hoofed mammalian herbivores. The Cottontail Rabbit also consumes the foliage. The sticky seedpods (loments) cling to the fur of animals and the clothing of humans. As a result, the seeds are carried to new locations.
Photographic Location: A sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: Among different populations of Panicled Tick Trefoil, there is significant variation in the width of the leaflets and the hairiness of the stems and leaflets. Usually, this wildflower has fairly narrow leaflets, hairless to nearly hairless stems, and hairless upper surfaces on the leaflets. It can be distinguished from other species in this genus by considering the following key characteristics: 1) the narrow leaflets are 3-6 times longer than they are across, 2) the petioles of the trifoliate leaves are fairly long (up to 2"), 3) the deciduous stipules of the trifoliate leaves are small and insignificant, and 4) the leaflets are rather long (up to 3½"). Panicled Tick Trefoil is one of the more common species of this genus in Illinois.
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Miss Chen
2018年03月08日
Description: This perennial wildflower is 2–3½' tall, branching occasionally. The stems are medium green to brown and sparsely to densely covered with both hooked and straight hairs. Alternate compound leaves occur at intervals along these stems; the structure of the leaves is trifoliate. Each compound leaf has a hairy petiole up to ½" long; at the base of each petiole, there is a pair of tiny deciduous stipules that are linear-lanceolate in shape. Individual leaflets are up to 2½" long and 1¼" across; they are oval to narrowly oval in shape, smooth and slightly ciliate along their margins, and rough-textured. Their upper surfaces are medium green and sparsely covered with short stiff hairs, while their lower surfaces are light green and covered with similar hairs. The terminal leaflet is larger in size than the lateral leaflets; the lateral leaflets have very short petiolules (secondary petioles), while the petiolule of the terminal leaflet is up to ½" long.
The upper stems terminate in either panicles or racemes of flowers about ½–1½' long and about one-third as much across or less. The central stalk of a panicle branches either oppositely or in whorls of 3. Both the central stalk and its lateral branches (if any) are covered with hooked hairs. Individual flowers occur on short pedicels up to ½" long. Each flower is about ¼" long, consisting of 5 pink to rosy pink petals, a very short tubular calyx that is toothed, an ovary with a single style, and several stamens. The flower has a pea-like structure, consisting of an upper banner and two lateral wings that enclose a lower keel. At the base of the banner, there is a small patch of yellow. The blooming period occurs from mid-summer to early fall and lasts about 1–1½ months. Fertile flowers are replaced by small loments (segmented flat seedpods) about ½–¾" long. Each loment usually consists of 2-3 segments; the lower side of each segment is more rounded than the upper side. Loments have veryDistribution Map short stipes and sometimes terminal beaks; their sides are covered with hooked hairs. Each segment of a loment contains a single seed. The root system consists of a narrow caudex with fibrous roots. This wildflower reproduces by reseeding itself, sometimes forming small colonies.
Cultivation: The preference is partial sun, dry-mesic conditions, and sandy or rocky soil. Nitrogen is added to the soil through a symbiotic association between the root system and mycorrhizal bacteria.
Range & Habitat: The native Obtuse-Leaved Tick Trefoil occurs in scattered locations in southern, western, and a few other areas in Illinois; it is uncommon within the state. Illinois lies along the NW range limit of this species. Habitats include open sandy woodlands, upland rocky woodlands, sandy savannas, woodland edges, rocky glades, and powerline clearances in sandy or rocky woodlands. Occasional wildfires or other disturbance tends to increase populations of this wildflower in the preceding habitats.
Faunal Associations: The flowers offer only pollen as a reward to insect visitors. These floral visitors consist primarily of bumblebees (Bombus spp.), long-horned bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.). Other insects feed on the foliage, flowers, seedpods, or plant juices of Desmodium spp. (Tick Trefoil species). These insect feeders include such skipper caterpillars as Achalarus lyciades (Hoary Edge), Thorybes bathyllus (Southern Cloudywing), Thorybes pylades (Northern Cloudywing), and Epargyreus clarus (Silver-Spotted Skipper); the caterpillars of the butterflies Everes comyntas (Eastern Tailed Blue) and Strymon melinus (Gray Hairstreak) also feed on these plants. Other insects feeders include various beetles, stink bugs, aphids, thrips, and moths (see Insect Table for a listing of these species). Among vertebrate animals, the seeds are eaten by some upland gamebirds (Bobwhite, Wild Turkey) and small rodents (White-Footed Mouse, Deer Mouse), while the foliage is browsed by White-Tailed Deer and the Cottontail Rabbit. The foliage is also palatable to cattle, horses, and sheep. The seedpods cling readily to the fur of animals and the clothing of humans; as a result, the seeds are distributed to new locations.
Photographic Location: A sandy savanna at the Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: This is one of several Desmodium spp. (Tick Trefoil species) in Illinois. Many of these species are found in savannas and open woodlands; their small pinkish flowers are very similar to each other. Obtuse-Leaved Tick Trefoil has wider leaflets than most other species in this genus (about 2-3 times as long as they are wide). Other critical features for identification include the following: 1) the stipules are tiny and deciduous, 2) the loments usually consist of only 2-3 segments, 3) the segments of the loments are rounded on both sides, although more so on their lower sides than their upper sides, and 4) the leaflets are relatively large (up to 2½" long and 1¼" across) and rough-textured. Another common name of this species is Stiff Tick Trefoil, which is derived from an obsolete scientific name, Desmodium rigidum.
The upper stems terminate in either panicles or racemes of flowers about ½–1½' long and about one-third as much across or less. The central stalk of a panicle branches either oppositely or in whorls of 3. Both the central stalk and its lateral branches (if any) are covered with hooked hairs. Individual flowers occur on short pedicels up to ½" long. Each flower is about ¼" long, consisting of 5 pink to rosy pink petals, a very short tubular calyx that is toothed, an ovary with a single style, and several stamens. The flower has a pea-like structure, consisting of an upper banner and two lateral wings that enclose a lower keel. At the base of the banner, there is a small patch of yellow. The blooming period occurs from mid-summer to early fall and lasts about 1–1½ months. Fertile flowers are replaced by small loments (segmented flat seedpods) about ½–¾" long. Each loment usually consists of 2-3 segments; the lower side of each segment is more rounded than the upper side. Loments have veryDistribution Map short stipes and sometimes terminal beaks; their sides are covered with hooked hairs. Each segment of a loment contains a single seed. The root system consists of a narrow caudex with fibrous roots. This wildflower reproduces by reseeding itself, sometimes forming small colonies.
Cultivation: The preference is partial sun, dry-mesic conditions, and sandy or rocky soil. Nitrogen is added to the soil through a symbiotic association between the root system and mycorrhizal bacteria.
Range & Habitat: The native Obtuse-Leaved Tick Trefoil occurs in scattered locations in southern, western, and a few other areas in Illinois; it is uncommon within the state. Illinois lies along the NW range limit of this species. Habitats include open sandy woodlands, upland rocky woodlands, sandy savannas, woodland edges, rocky glades, and powerline clearances in sandy or rocky woodlands. Occasional wildfires or other disturbance tends to increase populations of this wildflower in the preceding habitats.
Faunal Associations: The flowers offer only pollen as a reward to insect visitors. These floral visitors consist primarily of bumblebees (Bombus spp.), long-horned bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.). Other insects feed on the foliage, flowers, seedpods, or plant juices of Desmodium spp. (Tick Trefoil species). These insect feeders include such skipper caterpillars as Achalarus lyciades (Hoary Edge), Thorybes bathyllus (Southern Cloudywing), Thorybes pylades (Northern Cloudywing), and Epargyreus clarus (Silver-Spotted Skipper); the caterpillars of the butterflies Everes comyntas (Eastern Tailed Blue) and Strymon melinus (Gray Hairstreak) also feed on these plants. Other insects feeders include various beetles, stink bugs, aphids, thrips, and moths (see Insect Table for a listing of these species). Among vertebrate animals, the seeds are eaten by some upland gamebirds (Bobwhite, Wild Turkey) and small rodents (White-Footed Mouse, Deer Mouse), while the foliage is browsed by White-Tailed Deer and the Cottontail Rabbit. The foliage is also palatable to cattle, horses, and sheep. The seedpods cling readily to the fur of animals and the clothing of humans; as a result, the seeds are distributed to new locations.
Photographic Location: A sandy savanna at the Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: This is one of several Desmodium spp. (Tick Trefoil species) in Illinois. Many of these species are found in savannas and open woodlands; their small pinkish flowers are very similar to each other. Obtuse-Leaved Tick Trefoil has wider leaflets than most other species in this genus (about 2-3 times as long as they are wide). Other critical features for identification include the following: 1) the stipules are tiny and deciduous, 2) the loments usually consist of only 2-3 segments, 3) the segments of the loments are rounded on both sides, although more so on their lower sides than their upper sides, and 4) the leaflets are relatively large (up to 2½" long and 1¼" across) and rough-textured. Another common name of this species is Stiff Tick Trefoil, which is derived from an obsolete scientific name, Desmodium rigidum.
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