文章
Miss Chen
2018年03月29日
Description: This herbaceous perennial plant is ½–2' tall or long, branching occasionally. The stems are light green to brown, terete, and sparsely appressed-pubescent; they are erect, ascending, or sprawling. Alternate trifoliate leaves occur along these stems, becoming smaller in size toward the tips or apices of these stems. The leaflets are ½–1½" long and about one-half to one-third as much across; they are oblong-elliptic to broadly oblong-elliptic in shape and their margins are entire (toothless). Usually, the terminal leaflets are slightly larger in size than the lateral leaflets. The upper surface of these leaflets is medium green and hairless to sparsely appressed-pubescent, while the lower surface of these leaflets is light green or whitish green and moderately to densely appressed-pubescent. Leaflet venation is pinnate with prominent central veins and weaker lateral veins; the lateral veins are straight and run parallel to each other. Petioles of trifoliate leaves are ¼–1½" long; they are light green, terete, and sparsely appressed-pubescent. The petiolules (basal stalklets) of the terminal leaflets are 2-5 mm. long, while the petiolules of the lateral leaflets are 0.5–1 mm. long. At the bases of petioles along the stems, there are pairs of small stipules. These stipules are 2-5 mm. long and linear in shape; they have a tendency to wither early.
Leafy Plant with Seedpods
Racemes and/or sparingly branched panicles of 3-8 flowers are produced on long ascending peduncles from either the axils of upper leaves or directly from the upper stems. These peduncles extend beyond the compound leaves. The inflorescences are also produced from the axils of middle leaves, although their peduncles tend to be about as long as the petioles of compound leaves. Each flower is about 6-10 mm. in length, consisting of a light green calyx with 5 teeth, 5 whitish purple to purple petals, 10 stamens, and a pistil with a single style. The flowers have a typical pea-like floral structure, consisting of a large upright banner (upper petal), a pair of wings that are slightly spreading and extend forward (2 lower outer petals), and an inner keel that extends forward (2 lower inner petals). The wings of each flower are slightly shorter than its keel. At the base of the banner, there is an arch-shaped patch of dark rosy purple. The calyx is sparsely appressed pubescent and it extends to about one-half of the length of the flower. The pedicels of the flowers are short (1-4 mm. in length). In addition to the preceding chasmogamous flowers, there are also inconspicuous cleistogamous (self-fertile) flowers that develop from the axils of the leaves. These cleistogamous flowers are held close to the stems on short pedicels (1-4 mm. in length). The blooming period occurs from mid- to late summer, lasting about 1 month.
Afterwards, fertile flowers are replaced by small seedpods that become 4-7 mm. long at maturity, the latter changing in color from green to dark brown. Usually, the chasmogamous flowers don't produce seedpods, while the cleistogamous flowers almost always do. The seedpods are orbicular-ovate in shape and flattened, tapering abruptly at their tips into short beaks; they are sparsely appressed-pubescent along their sides. Each seedpod contains a single reniform (kidney-shaped) seed. The root system consists of a taproot.
Cultivation: The preference is partial sun, dry-mesic conditions, and somewhat sterile soil containing some clay or rocky material. Competition from taller and more aggressive ground vegetation is not well-tolerated. This legume fixes nitrogen in the soil.
Range & Habitat: The native Violet Bush Clover is occasional in the southern half of Illinois, while in the northern half of the state it is uncommon (see Distribution Map). However, it can be found in scattered areas throughout the state. Habitats include upland rocky woodlands, thinly wooded bluffs along rivers, upland savannas, hill prairies, dry grassy openings in upland woodlands, and roadside embankments along hilly woodlands. Violet Bush Clover is found primarily in average to high quality natural areas. It probably benefits from occasional wildfires that reduce competition from woody vegetation.
Faunal Associations: The chasmogamous flowers of Violet Bush Clover are cross-pollinated primarily by bees, including leaf-cutting bees (Megachile spp.), digger bees (Melissodes spp.) and Halictid bees. Small butterflies and skippers may also visit these flowers, but they are less effective at cross-pollination. The showier chasmogamous flowers of Violet Bush Clover probably require insect cross-pollination before they can produce seedpods, while the cleistogamous flowers do not. Miscellaneous insects feed destructively on the foliage, seeds, and other parts of bush clovers (Lespedeza spp.). These insects include the seed-eating larvae of a weevil (Coelocephalapion decoloratum), various leaf beetles and their larvae (Anomoea laticlavia, Odontota horni, Phyllecthris dorsalis, etc.), foliage-eating larvae of a sawfly (Atomacera debilis), seed-eating broad-headed bugs (Alydus spp.), an aphid (Microparsus singularis), the Prairie Walking Stick (Diapheromera velii), and Tick Trefoil Thrips (Neohydatothrips desmodianus); see Sauer (2005), Clark et al. (2004), Smith (2006), Schaefer (1980), Blackman & Eastop (2013), Arment (2006), and Stannard (1968). The caterpillars of some skippers feed on the foliage of bush clovers; these species include the Hoary Edge (Achalarus lyciades), Southern Duskywing (Thorybes bathyllus), and Northern Duskywing (Thorybes pylades). In addition, the larvae of some moths feed on these plants. Examples of such moths include the Bella Moth (Utetheisa bella), Common Ptichodis (Ptichodis herbarum), Black-spotted Prominent (Dasylophia anguina), a Cosmopterigid moth (Triclonella pergandeella), and a Gracillariid moth (Parectopa lespedezaefoliella); see Opler & Krizek (1984) Covell (1984/2005), and Needham et al. (1928). The larvae of the last two moths are leaf-miners. Among vertebrate animals, the seeds of bush clovers are eaten by the Ruffed Grouse, Wild Turkey, Bobwhite Quail, Mourning Dove, and Slate-colored Junco; they are also eaten by the Prairie Deer Mouse. The foliage is palatable to White-tailed Deer and other hoofed mammalian herbivores, including cattle (Martin et al., 1951/1961; Whitaker, 1966; Georgia, 1913).
Photographic Location: A grassy opening of an upland woodland at Merwin Nature Preserve in McLain County, Illinois.
Comments: In the past, Violet Bush Clover was referred to as Lespedeza violacea, while another species, Wand-like Bush Clover, was referred to as Lespedeza intermedia. However, it is now thought that the original herbarium specimen of Lespedeza violacea actually refers to Wand-like Bush Clover. Therefore, the appropriate scientific name for Violet Bush Clover (as described here) is Lespedeza frutescens. This changeover in names will be, no doubt, a source of confusion in the future. Because the flowers of Violet Bush Clover are more violet than those of Wand-like Bush Clover, the common names have been retained. Violet Bush Clover is one of several bush clovers (Lespedeza spp.) that occur in Illinois; most of them are native. It can be distinguished from similar species by its semi-erect habit, the long peduncles of its inflorescences (for chasmogamous flowers), the presence of inconspicuous cleistogamous flowers near its stems, and the structure of its flowers (their wings are shorter than their keels). Other bush clovers are either more erect or they are widely spreading vines. Bush clovers can be distinguished from similar-appearing tick trefoils (Desmodium spp.) by their seedpods: bush clovers have short single-seeded pods that are non-sticky, while tick trefoils have longer multiseeded pods that can cling to various surfaces by their hooked hairs.
Leafy Plant with Seedpods
Racemes and/or sparingly branched panicles of 3-8 flowers are produced on long ascending peduncles from either the axils of upper leaves or directly from the upper stems. These peduncles extend beyond the compound leaves. The inflorescences are also produced from the axils of middle leaves, although their peduncles tend to be about as long as the petioles of compound leaves. Each flower is about 6-10 mm. in length, consisting of a light green calyx with 5 teeth, 5 whitish purple to purple petals, 10 stamens, and a pistil with a single style. The flowers have a typical pea-like floral structure, consisting of a large upright banner (upper petal), a pair of wings that are slightly spreading and extend forward (2 lower outer petals), and an inner keel that extends forward (2 lower inner petals). The wings of each flower are slightly shorter than its keel. At the base of the banner, there is an arch-shaped patch of dark rosy purple. The calyx is sparsely appressed pubescent and it extends to about one-half of the length of the flower. The pedicels of the flowers are short (1-4 mm. in length). In addition to the preceding chasmogamous flowers, there are also inconspicuous cleistogamous (self-fertile) flowers that develop from the axils of the leaves. These cleistogamous flowers are held close to the stems on short pedicels (1-4 mm. in length). The blooming period occurs from mid- to late summer, lasting about 1 month.
Afterwards, fertile flowers are replaced by small seedpods that become 4-7 mm. long at maturity, the latter changing in color from green to dark brown. Usually, the chasmogamous flowers don't produce seedpods, while the cleistogamous flowers almost always do. The seedpods are orbicular-ovate in shape and flattened, tapering abruptly at their tips into short beaks; they are sparsely appressed-pubescent along their sides. Each seedpod contains a single reniform (kidney-shaped) seed. The root system consists of a taproot.
Cultivation: The preference is partial sun, dry-mesic conditions, and somewhat sterile soil containing some clay or rocky material. Competition from taller and more aggressive ground vegetation is not well-tolerated. This legume fixes nitrogen in the soil.
Range & Habitat: The native Violet Bush Clover is occasional in the southern half of Illinois, while in the northern half of the state it is uncommon (see Distribution Map). However, it can be found in scattered areas throughout the state. Habitats include upland rocky woodlands, thinly wooded bluffs along rivers, upland savannas, hill prairies, dry grassy openings in upland woodlands, and roadside embankments along hilly woodlands. Violet Bush Clover is found primarily in average to high quality natural areas. It probably benefits from occasional wildfires that reduce competition from woody vegetation.
Faunal Associations: The chasmogamous flowers of Violet Bush Clover are cross-pollinated primarily by bees, including leaf-cutting bees (Megachile spp.), digger bees (Melissodes spp.) and Halictid bees. Small butterflies and skippers may also visit these flowers, but they are less effective at cross-pollination. The showier chasmogamous flowers of Violet Bush Clover probably require insect cross-pollination before they can produce seedpods, while the cleistogamous flowers do not. Miscellaneous insects feed destructively on the foliage, seeds, and other parts of bush clovers (Lespedeza spp.). These insects include the seed-eating larvae of a weevil (Coelocephalapion decoloratum), various leaf beetles and their larvae (Anomoea laticlavia, Odontota horni, Phyllecthris dorsalis, etc.), foliage-eating larvae of a sawfly (Atomacera debilis), seed-eating broad-headed bugs (Alydus spp.), an aphid (Microparsus singularis), the Prairie Walking Stick (Diapheromera velii), and Tick Trefoil Thrips (Neohydatothrips desmodianus); see Sauer (2005), Clark et al. (2004), Smith (2006), Schaefer (1980), Blackman & Eastop (2013), Arment (2006), and Stannard (1968). The caterpillars of some skippers feed on the foliage of bush clovers; these species include the Hoary Edge (Achalarus lyciades), Southern Duskywing (Thorybes bathyllus), and Northern Duskywing (Thorybes pylades). In addition, the larvae of some moths feed on these plants. Examples of such moths include the Bella Moth (Utetheisa bella), Common Ptichodis (Ptichodis herbarum), Black-spotted Prominent (Dasylophia anguina), a Cosmopterigid moth (Triclonella pergandeella), and a Gracillariid moth (Parectopa lespedezaefoliella); see Opler & Krizek (1984) Covell (1984/2005), and Needham et al. (1928). The larvae of the last two moths are leaf-miners. Among vertebrate animals, the seeds of bush clovers are eaten by the Ruffed Grouse, Wild Turkey, Bobwhite Quail, Mourning Dove, and Slate-colored Junco; they are also eaten by the Prairie Deer Mouse. The foliage is palatable to White-tailed Deer and other hoofed mammalian herbivores, including cattle (Martin et al., 1951/1961; Whitaker, 1966; Georgia, 1913).
Photographic Location: A grassy opening of an upland woodland at Merwin Nature Preserve in McLain County, Illinois.
Comments: In the past, Violet Bush Clover was referred to as Lespedeza violacea, while another species, Wand-like Bush Clover, was referred to as Lespedeza intermedia. However, it is now thought that the original herbarium specimen of Lespedeza violacea actually refers to Wand-like Bush Clover. Therefore, the appropriate scientific name for Violet Bush Clover (as described here) is Lespedeza frutescens. This changeover in names will be, no doubt, a source of confusion in the future. Because the flowers of Violet Bush Clover are more violet than those of Wand-like Bush Clover, the common names have been retained. Violet Bush Clover is one of several bush clovers (Lespedeza spp.) that occur in Illinois; most of them are native. It can be distinguished from similar species by its semi-erect habit, the long peduncles of its inflorescences (for chasmogamous flowers), the presence of inconspicuous cleistogamous flowers near its stems, and the structure of its flowers (their wings are shorter than their keels). Other bush clovers are either more erect or they are widely spreading vines. Bush clovers can be distinguished from similar-appearing tick trefoils (Desmodium spp.) by their seedpods: bush clovers have short single-seeded pods that are non-sticky, while tick trefoils have longer multiseeded pods that can cling to various surfaces by their hooked hairs.
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Miss Chen
2018年03月29日
Description: This perennial plant is ½–1½' tall and abundantly branched, particularly along the upper two-thirds of its length. The pale green stems are sparsely to moderately covered with white hairs that are upwardly appressed or ascending. Small leaves about 8-15 mm. (1/3–2/3") long and about one-third as much across occur along the stems: they are alternate,Seed Capsules & Leafy Bracts opposite, or whorled. The leaf blades are green (turning yellow during the fall), smooth and ciliate along their margins, and elliptic-oblong with blunt tips; the base of each leaf blade is sessile, or it is has a short petiole. The upper surfaces of the blades are hairless to sparsely hairy, while the lower surfaces of the blades are usually hairy, particularly along the midveins. Similar to the hairs on the stems, the hairs on the leaves are appressed or curve outward toward their tips. The middle to upper stems produce overlapping panicles of flowers. Individual panicles are longer than they are wide, and they produce leafy bracts that are similar to the leaves, except the former are smaller in size. The small flowers are borne individually on the secondary and tertiary branches of the panicles. Each flower is about 2 mm. long and a little less across, consisting of 5 persistent purplish red petals, 5 ascending green sepals (sometimes becoming red later), 3 or more stamens, and a 3-celled ovary with short stigmata at its apex (there are no filaments). Each flower has a short slender pedicel about 1 mm. long. The blooming period occurs during the late summer for about a month; only a few flowers are in bloom at the same time. The flowers are probably cross-pollinated by wind, at least in part. Each flower is replaced by an ovoid seed capsule about 2 mm. long that typically contains 2-3 seeds; because of the persistent petals and sepals, it is purplish red or greenish red in appearance. The 2 outer sepals are the same length or longer than the seed capsule (2 mm. in length or more) and they are linear in shape. The 3 inner sepals are shorter than the seed capsule (less than 2 mm. in length) and they are ovate in shape. After the seed capsules open, the small seeds are dispersed primarily by gravity and usually fall only a short distance from the mother plant. During the late fall, the flowering plant withers away and it is replaced by a low rosette of little-branched stems with whorled or opposite leaves; this rosette spans about 3-4" across and usually survives the winter until it is replaced by a flowering plant during the next spring. The basal leaves are similar to the cauline leaves of the flowering plant, except they are more wide in shape (oval-ovate). The root system consists of a slender taproot with fibrous secondary roots; sometimes the taproot is barely distinguishable from these secondary roots.
Cultivation: The preference is full or partial sun, moist to dry conditions, and either sandy or very rocky soil. The seeds are slow to germinate, often remaining dormant for several years.
Range & Habitat: The native Small Pinweed is an uncommon plant that is found in NE Illinois and scattered locations elsewhere in the state (see Distribution Map). Habitats include sand prairies, openings and edges of sandy oak woodlands, sandy oak savannas, rocky bluffs and cliffs, partially wooded sand dunes near Lake Michigan, and edges of sandy marshes. In many areas, populations of Small Pinweed have declined as a result of habitat destruction from various development projects. Like other Lechea spp. (Pinweeds), it is adapted to occasional disturbance (wildfires, shifting dunes), but dislikes extreme orLower Stem & Leaves more frequent modifications of its environment.
Faunal Associations: In general, very little is known about the floral-fauna relationships of Lechea spp. (Pinweeds); they have not been studied adequately, thus some of the following information is speculative. The flowers offer no nectar to insect visitors; only pollen is available as a food reward. It is possible that various flies, small bees, and other small insects are minor pollinators of the flowers, which are self-fertile and probably cross-pollinated by the wind. It has been found that White-Tailed Deer preferentially browse on Lechea maritima (Beach Pinweed) in Virginia (see Keiper, 1990), and thus they may browse on other Pinweeds in other areas as well.
Photographic Location: Edge of a sandy oak woodland that is located near a wet sand prairie at the Iroquois County Conservation Area in Iroquois County, Illinois.
Comments: In most of Illinois, Lechea spp. (Pinweeds) are restricted to sandy habitats, although in southern Illinois some species (including Small Pinweed) can be found along cliffs and upland woodlands that are rocky. The various species are very similar to each other in appearance and can be difficult to differentiate. The presence of mature fruits on a prospective plant greatly facilitates its identification and, to a lesser extent, the shape of the leaves and type of hairs on the stems facilitates species identification as well. Small Pinweed can be distinguished from other similar Pinweed species as follows: 1) it has wider leaves than some other species, which are more linear in shape, 2) the hairs on its stems are upwardly appressed or ascending, rather than widely spreading or absent, 3) the seed capsules are ovoid in shape, rather than globoid or subgloboid, and 4) the outer sepals of Small Pinweed are longer than the inner sepals and they are as long or longer than the seed capsules. The only other Pinweed in Illinois with the last characteristic is Lechea tenuifolia (Slender Pinweed), which differs by having linear leaves and it tends to be smaller in size. Another common name of Lechea minor is Thyme-Leaved Pinweed.
Cultivation: The preference is full or partial sun, moist to dry conditions, and either sandy or very rocky soil. The seeds are slow to germinate, often remaining dormant for several years.
Range & Habitat: The native Small Pinweed is an uncommon plant that is found in NE Illinois and scattered locations elsewhere in the state (see Distribution Map). Habitats include sand prairies, openings and edges of sandy oak woodlands, sandy oak savannas, rocky bluffs and cliffs, partially wooded sand dunes near Lake Michigan, and edges of sandy marshes. In many areas, populations of Small Pinweed have declined as a result of habitat destruction from various development projects. Like other Lechea spp. (Pinweeds), it is adapted to occasional disturbance (wildfires, shifting dunes), but dislikes extreme orLower Stem & Leaves more frequent modifications of its environment.
Faunal Associations: In general, very little is known about the floral-fauna relationships of Lechea spp. (Pinweeds); they have not been studied adequately, thus some of the following information is speculative. The flowers offer no nectar to insect visitors; only pollen is available as a food reward. It is possible that various flies, small bees, and other small insects are minor pollinators of the flowers, which are self-fertile and probably cross-pollinated by the wind. It has been found that White-Tailed Deer preferentially browse on Lechea maritima (Beach Pinweed) in Virginia (see Keiper, 1990), and thus they may browse on other Pinweeds in other areas as well.
Photographic Location: Edge of a sandy oak woodland that is located near a wet sand prairie at the Iroquois County Conservation Area in Iroquois County, Illinois.
Comments: In most of Illinois, Lechea spp. (Pinweeds) are restricted to sandy habitats, although in southern Illinois some species (including Small Pinweed) can be found along cliffs and upland woodlands that are rocky. The various species are very similar to each other in appearance and can be difficult to differentiate. The presence of mature fruits on a prospective plant greatly facilitates its identification and, to a lesser extent, the shape of the leaves and type of hairs on the stems facilitates species identification as well. Small Pinweed can be distinguished from other similar Pinweed species as follows: 1) it has wider leaves than some other species, which are more linear in shape, 2) the hairs on its stems are upwardly appressed or ascending, rather than widely spreading or absent, 3) the seed capsules are ovoid in shape, rather than globoid or subgloboid, and 4) the outer sepals of Small Pinweed are longer than the inner sepals and they are as long or longer than the seed capsules. The only other Pinweed in Illinois with the last characteristic is Lechea tenuifolia (Slender Pinweed), which differs by having linear leaves and it tends to be smaller in size. Another common name of Lechea minor is Thyme-Leaved Pinweed.
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Miss Chen
2018年03月27日
Description: This herbaceous perennial plant consists of a twining vine up to 20-30' long. It will climb adjacent vegetation readily, or sprawl across the ground in open areas. The terete stems are usually hairless, but sometimes pubescent, and often reddish purple. Along the stems are alternate leaves up to 6" long and 4" across. These leaves are usually cordate and hairless, although sometimes the smaller leaves are ovate. They have long hairless petioles and smooth margins. Both the upper and lower surfaces of the leaves are olive green, while the petioles are often reddish purple.
Flowering stalks develop from the axils of the leaves; each flowering stalk has a cluster of 1-5 funnelform flowers. The corolla of each flower is white, except for rosy pink or reddish purple coloration deep within its throat. The corolla has 5 shallow lobes; it is about 2½-3" across when it is fully open and similarly in length. The stamens of the flower are white; they project slightly from the throat of the corolla. The blunt overlapping sepals are light green, hairless, and about ½-¾" long; they often have narrow ridges. The flowers bloom during the morning (or during the afternoon on cloudy days), and they are individually short-lived. However, a typical plant will bloom for about 2 months during mid- to late summer. Each flower is replaced by a 2-celled capsule that contains 2-4 seeds. These flat seeds are conspicuously hairy along their outer edges, and pubescent elsewhere. The root system produces a large tuber that can lie several feet beneath the ground surface and weigh up to 20-30 lb.
Cultivation: The preference is full to partial sun and mesic to dry conditions. The type of soil is not particularly important; this plant often grows where there are rocky or gravelly slopes. Growth can be rampant where the soil is moist and fertile; this plant can smother surrounding vegetation and it prefers some kind of structural support. Drought resistance is very good.
Range & Habitat: The native Wild Sweet Potato occurs occasionally in most counties of Illinois, except in the extreme north and NW areas of the state, where it is uncommon or absent (see Distribution Map). Habitats include upland woodlands, edges of prairies near woodlands, rocky streambanks, thickets, fence rows, abandoned fields, and areas along railroads and roadsides. This plant is more often seen in disturbed habitats, but it can be found in higher quality habitats as well.
Faunal Associations: The flowers primarily attract long-tongued bees, including honeybees, bumblebees, and digger bees (Melissodes spp.). Some oligolectic bees that visit the flowers of the Wild Sweet Potato and other Ipomoea spp. include Melitoma taurea (Mallow Bee) and Cemolobus ipomoea (Morning Glory Bee). These insects seek nectar primarily, although the oligolectic bees collect pollen as well. Less common visitors to the flowers include nectar-seeking swallowtail butterflies, skippers, and sphinx moths. Like other Ipomoea spp., Wild Sweet Potato attracts numerous tortoise beetles and other beetles that feed on the foliage. These species include Agroiconota bivittata (Striped Tortoise Beetle), Charidotella purpurata (Tortoise Beetle sp.), Charidotella sexpunctata (Golden Tortoise Beetle), Chelymorpha cassidea (Argus Tortoise Beetle), Jonthonota nigripes (Black-Legged Tortoise Beetle), Opacinota bisignata (Tortoise Beetle sp.), Strongylocassis atripes (Tortoise Beetle sp.), Chaetocnema confinis (Sweet Potato Flea Beetle), and Typophorus nigritus (Sweet Potato Leaf Beetle). Larvae of the Sweet Potato Flea Beetle and Sweet Potato Leaf Beetle also feed on the roots. Larvae of a long-horned beetle, Phaea monostigma, bore through the stems of Ipomoea spp. The caterpillars of such moths as Agrius cingulatus (Pink-Spotted Hawk Moth), Bedellia somnulentella (Sweet Potato Leaf-Miner), and Emmelina monodactyla (Morning Glory Plume Moth) also feed on these plants. Because the foliage is bitter and somewhat toxic, it is avoided by mammalian herbivores as a food source. Because its long leafy stems often form dense thicket tangles, Wild Sweet Potato provides excellent cover for birds and other kinds of wildlife during the summer and early fall.
Photographic Location: The photographs were taken near an abandoned railroad in Champaign County, Illinois. The plant was growing along a gravelly slope, where it clambered over Conium maculatum (Poison Hemlock).
Comments: The common name of this plant species refers to the large tuberous root, which is edible (barely) after being cooked. Another common name, Man-of-the-Earth, also refers to this large tuberous root. It was one of the food sources of native Amerindians. The Wild Sweet Potato is fairly easy to distinguish from other members of the Morning Glory family by its large white flowers with pinkish purple throats and its heart-shaped leaves. Perhaps its most unusual feature (aside from the root) is the hairiness of its seeds; other Morning Glory and Bindweed species usually have smooth seeds.
Flowering stalks develop from the axils of the leaves; each flowering stalk has a cluster of 1-5 funnelform flowers. The corolla of each flower is white, except for rosy pink or reddish purple coloration deep within its throat. The corolla has 5 shallow lobes; it is about 2½-3" across when it is fully open and similarly in length. The stamens of the flower are white; they project slightly from the throat of the corolla. The blunt overlapping sepals are light green, hairless, and about ½-¾" long; they often have narrow ridges. The flowers bloom during the morning (or during the afternoon on cloudy days), and they are individually short-lived. However, a typical plant will bloom for about 2 months during mid- to late summer. Each flower is replaced by a 2-celled capsule that contains 2-4 seeds. These flat seeds are conspicuously hairy along their outer edges, and pubescent elsewhere. The root system produces a large tuber that can lie several feet beneath the ground surface and weigh up to 20-30 lb.
Cultivation: The preference is full to partial sun and mesic to dry conditions. The type of soil is not particularly important; this plant often grows where there are rocky or gravelly slopes. Growth can be rampant where the soil is moist and fertile; this plant can smother surrounding vegetation and it prefers some kind of structural support. Drought resistance is very good.
Range & Habitat: The native Wild Sweet Potato occurs occasionally in most counties of Illinois, except in the extreme north and NW areas of the state, where it is uncommon or absent (see Distribution Map). Habitats include upland woodlands, edges of prairies near woodlands, rocky streambanks, thickets, fence rows, abandoned fields, and areas along railroads and roadsides. This plant is more often seen in disturbed habitats, but it can be found in higher quality habitats as well.
Faunal Associations: The flowers primarily attract long-tongued bees, including honeybees, bumblebees, and digger bees (Melissodes spp.). Some oligolectic bees that visit the flowers of the Wild Sweet Potato and other Ipomoea spp. include Melitoma taurea (Mallow Bee) and Cemolobus ipomoea (Morning Glory Bee). These insects seek nectar primarily, although the oligolectic bees collect pollen as well. Less common visitors to the flowers include nectar-seeking swallowtail butterflies, skippers, and sphinx moths. Like other Ipomoea spp., Wild Sweet Potato attracts numerous tortoise beetles and other beetles that feed on the foliage. These species include Agroiconota bivittata (Striped Tortoise Beetle), Charidotella purpurata (Tortoise Beetle sp.), Charidotella sexpunctata (Golden Tortoise Beetle), Chelymorpha cassidea (Argus Tortoise Beetle), Jonthonota nigripes (Black-Legged Tortoise Beetle), Opacinota bisignata (Tortoise Beetle sp.), Strongylocassis atripes (Tortoise Beetle sp.), Chaetocnema confinis (Sweet Potato Flea Beetle), and Typophorus nigritus (Sweet Potato Leaf Beetle). Larvae of the Sweet Potato Flea Beetle and Sweet Potato Leaf Beetle also feed on the roots. Larvae of a long-horned beetle, Phaea monostigma, bore through the stems of Ipomoea spp. The caterpillars of such moths as Agrius cingulatus (Pink-Spotted Hawk Moth), Bedellia somnulentella (Sweet Potato Leaf-Miner), and Emmelina monodactyla (Morning Glory Plume Moth) also feed on these plants. Because the foliage is bitter and somewhat toxic, it is avoided by mammalian herbivores as a food source. Because its long leafy stems often form dense thicket tangles, Wild Sweet Potato provides excellent cover for birds and other kinds of wildlife during the summer and early fall.
Photographic Location: The photographs were taken near an abandoned railroad in Champaign County, Illinois. The plant was growing along a gravelly slope, where it clambered over Conium maculatum (Poison Hemlock).
Comments: The common name of this plant species refers to the large tuberous root, which is edible (barely) after being cooked. Another common name, Man-of-the-Earth, also refers to this large tuberous root. It was one of the food sources of native Amerindians. The Wild Sweet Potato is fairly easy to distinguish from other members of the Morning Glory family by its large white flowers with pinkish purple throats and its heart-shaped leaves. Perhaps its most unusual feature (aside from the root) is the hairiness of its seeds; other Morning Glory and Bindweed species usually have smooth seeds.
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Miss Chen
2018年03月27日
Description: This perennial herbaceous plant is 1-4' tall and unbranched. The central stem is light green to purple, terete, glabrous to short-pubescent below, and short-pubescent above. About 6-30 alternate leaves are distributed evenly along the length of the stem; the leaves remain the same size, or become slightly smaller in size, as they ascend the stem. Individual leaves are 1½–4" long ¼–1¼" across; the length and width of these leaves varies with the robustness of the plant and the local ecotype or variety. Leaf shape is elliptic, lanceolate-elliptic, lanceolate, or lanceolate-ovate, while leaf margins are sparsely dentate, sparsely denticulate (minutely dentate), or smooth. The upper leaf surface is pale-medium to medium green and glabrous, while the lower leaf surface is pale green and glabrous to short-pubescent. Leaf bases are rounded to narrowly wedge-shaped, while their tips are acute. The leaves are either sessile or they clasp the stem; a few leaves may have short petioles (3 mm. or less) that are appressed against the stem.
The central stem terminates in a panicle of flowerheads that is often corymb-like in shape; a large panicle may have more than one corymb-like division. The size of these panicles is 3-20" long and 5-10" across; small panicles are sometimes more wide than they are across, while large panicles are longer in length than they are across. The branches of each panicle are light green, terete, short-pubescent, and largely naked; a few leafy bracts up to ¼" long may be present. The terminal branches produce individual flowerheads about ¾-1¼" across. Each flowerhead has 30-80 ray florets and no disk florets. The petaloid extensions (or rays) of these florets are bright yellow and narrowly oblong in shape; their tips are 5-toothed and truncate. The base of each flowerhead is surrounded by narrow green phyllaries in 2-3 series. The outermost phyllaries are the smallest. These phyllaries are glabrous or short-hairy; sometimes they have short glandular hairs. The blooming period occurs from mid-summer to early fall, lasting about 3-4 weeks for a colony of plants. In the absence of cross-pollination from other plants, the florets are self-fertile. Shortly afterwards, the florets are replaced by small achenes with sessile tufts of light brown hair. The achenes are about 2.5–3 mm. in length, bullet-shaped, ribbed along their sides, and truncate at their apices. They are distributed by the wind. The root system is fibrous, sometimes forming clonal offsets. On older plants, a small caudex may develop.
Cultivation: The preference is full sun to light shade, mesic to dry conditions, and either sandy or rocky soil. This plant dislikes hot summer weather (90°F or higher temperatures). Plant size can vary considerably depending on the habitat, weather, and local ecotype.
Range & Habitat: Northern Hawkweed is occasional in northern Illinois, where it is native (see Distribution Map). It also occurs in Eurasia, although the latter continental mass has varieties that are distinct from those in North America. Habitats include sandy upland savannas, sand prairies, stabilized sand dunes, openings in sandy or rocky woodlands, sandy thickets, sandy fields, and roadsides. Northern Hawkweed can be found in either high quality or disturbed habitats. It probably benefits from occasional wildfires if this reduces competing woody vegetation.
Faunal Associations: Various bees and probably other insects visit the flowerheads for nectar and/or pollen, including Halictid bees. Some aphids suck plant juices from the flowering stems and other parts of hawkweeds (Hieracium spp.); these species include Hyperomyzus inflatus, Nasonovia ribisnigri (Currant-Lettuce Aphid), Uroleucon hieracicola (Hawkweed Aphid), and Uroleucon sonchi (Sow-Thistle Aphid). Another insect, the plant bug Lygus rubroclarus, feeds on hawkweeds and other members of the Aster family. These plants are also suspected hosts of Schinia bina (Bina Flower Moth). Among vertebrate animals, the Ruffed Grouse and Wild Turkey eat the seeds and leaves of hawkweeds to some extent; the Cottontail Rabbit and White-Tailed Deer also browse on the leaves (Martin et al., 1951/1961).
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: Northern Hawkweed is one of the showier native hawkweeds (Hieracium spp.) because it has larger flowerheads (about 1" across) than most. It also produces more leaves along its stems, and the branches of its inflorescence are short-pubescent, rather than glandular-hairy. The taxonomy of this hawkweed, at least in North America, is somewhat confused. In addition to Hieracium umbellatum (Northern Hawkweed), this plant is also referred to as Hieracium canadense (Canada Hawkweed) and Hieracium kalmii (Kalm's Hawkweed). The view taken here is that Hieracium umbellatum is a highly variable species that subsumes both Eurasian and North American plants. The primary difficulty in North America is that leaf width and the amount of dentition along leaf margins are highly variable. Populations of plants in northeastern United States and southeastern Canada tend to have wider leaves with more strongly defined teeth, while populations of plants in the upper midwest of the United States and south-central Canada tend to have more narrow leaves with poorly defined teeth. In Eurasia, this plant tends to have even more narrow leaves than what is observed in North America. These and other variations have led to the description of different varieties and subspecies that have varied in their popularity across time. Another common name of Hieracium umbellatum is Narrow-Leaved Hawkweed.
The central stem terminates in a panicle of flowerheads that is often corymb-like in shape; a large panicle may have more than one corymb-like division. The size of these panicles is 3-20" long and 5-10" across; small panicles are sometimes more wide than they are across, while large panicles are longer in length than they are across. The branches of each panicle are light green, terete, short-pubescent, and largely naked; a few leafy bracts up to ¼" long may be present. The terminal branches produce individual flowerheads about ¾-1¼" across. Each flowerhead has 30-80 ray florets and no disk florets. The petaloid extensions (or rays) of these florets are bright yellow and narrowly oblong in shape; their tips are 5-toothed and truncate. The base of each flowerhead is surrounded by narrow green phyllaries in 2-3 series. The outermost phyllaries are the smallest. These phyllaries are glabrous or short-hairy; sometimes they have short glandular hairs. The blooming period occurs from mid-summer to early fall, lasting about 3-4 weeks for a colony of plants. In the absence of cross-pollination from other plants, the florets are self-fertile. Shortly afterwards, the florets are replaced by small achenes with sessile tufts of light brown hair. The achenes are about 2.5–3 mm. in length, bullet-shaped, ribbed along their sides, and truncate at their apices. They are distributed by the wind. The root system is fibrous, sometimes forming clonal offsets. On older plants, a small caudex may develop.
Cultivation: The preference is full sun to light shade, mesic to dry conditions, and either sandy or rocky soil. This plant dislikes hot summer weather (90°F or higher temperatures). Plant size can vary considerably depending on the habitat, weather, and local ecotype.
Range & Habitat: Northern Hawkweed is occasional in northern Illinois, where it is native (see Distribution Map). It also occurs in Eurasia, although the latter continental mass has varieties that are distinct from those in North America. Habitats include sandy upland savannas, sand prairies, stabilized sand dunes, openings in sandy or rocky woodlands, sandy thickets, sandy fields, and roadsides. Northern Hawkweed can be found in either high quality or disturbed habitats. It probably benefits from occasional wildfires if this reduces competing woody vegetation.
Faunal Associations: Various bees and probably other insects visit the flowerheads for nectar and/or pollen, including Halictid bees. Some aphids suck plant juices from the flowering stems and other parts of hawkweeds (Hieracium spp.); these species include Hyperomyzus inflatus, Nasonovia ribisnigri (Currant-Lettuce Aphid), Uroleucon hieracicola (Hawkweed Aphid), and Uroleucon sonchi (Sow-Thistle Aphid). Another insect, the plant bug Lygus rubroclarus, feeds on hawkweeds and other members of the Aster family. These plants are also suspected hosts of Schinia bina (Bina Flower Moth). Among vertebrate animals, the Ruffed Grouse and Wild Turkey eat the seeds and leaves of hawkweeds to some extent; the Cottontail Rabbit and White-Tailed Deer also browse on the leaves (Martin et al., 1951/1961).
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: Northern Hawkweed is one of the showier native hawkweeds (Hieracium spp.) because it has larger flowerheads (about 1" across) than most. It also produces more leaves along its stems, and the branches of its inflorescence are short-pubescent, rather than glandular-hairy. The taxonomy of this hawkweed, at least in North America, is somewhat confused. In addition to Hieracium umbellatum (Northern Hawkweed), this plant is also referred to as Hieracium canadense (Canada Hawkweed) and Hieracium kalmii (Kalm's Hawkweed). The view taken here is that Hieracium umbellatum is a highly variable species that subsumes both Eurasian and North American plants. The primary difficulty in North America is that leaf width and the amount of dentition along leaf margins are highly variable. Populations of plants in northeastern United States and southeastern Canada tend to have wider leaves with more strongly defined teeth, while populations of plants in the upper midwest of the United States and south-central Canada tend to have more narrow leaves with poorly defined teeth. In Eurasia, this plant tends to have even more narrow leaves than what is observed in North America. These and other variations have led to the description of different varieties and subspecies that have varied in their popularity across time. Another common name of Hieracium umbellatum is Narrow-Leaved Hawkweed.
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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25日
Gardeners have long known that some plants seem to grow better when grouped together, while others seem to conflict. Companion planting is a gardening technique that emphasizes plant compatibility; for instance, climbing vines and tall plants, such as tomatoes and corn, work well when paired with low-growing crops, such as beets and cucumbers, since they do not compete with each other for space.
Companion Planting
Choosing plants that are able to share space harmoniously allows gardeners to place different specimens close together, maximizing the productivity of a given area. The secret to successful companion planting is choosing vegetables that balance each other and have similar environmental needs. Vegetables that compete for nutrients, sunlight, or root space make poor companions. For example, tall, heat-loving, long-season plants are complemented by short-season, ground-hugging plants or small, below-ground crops.
Tomatoes
Tomatoes are a vegetable garden favorite, but they are also heat lovers that require full sun. As such, they cannot be planted beneath other garden plants. However, the area around the base of a tomato plant is often an ideal location for shallow-rooted, shade-tolerant plants, or bite-sized root vegetables. Surround tomatoes with beets, baby carrots, garlic, green onions, sage, chives and marigolds for the best results; not only to these plants grow well in the shade provided by towering tomato plants, they seem to improve the productivity of the tomato vines.
Beets
Beets are valued for both their flavorsome roots and their leafy tops. They are well adapted to most climates and flourish when set in full sun or partial shade; however, they tend to grow best in temperate regions and flourish when planted near bok choy, broccoli, cauliflower, bush beans, cabbage or tomatoes. This mid-season plant can be set out three weeks before the expected date of the final frost. Once the young sprouts emerge, they are ready to harvest 48 to 50 days later. This opens up a small area of the garden that can then be replanted with a short-season vegetable such as radishes or lettuce.
Spacing
Companion plants can be set fairly close together, saving valuable garden space. To determine the appropriate distance between companion plants, combine the suggested spacing for each plant, then divide the total by two. For example, beets should be spaced 4 inches apart, and tomatoes should have at least 24 inches of room between them. Allow at least 16 inches between beets and tomatoes.
Companion Planting
Choosing plants that are able to share space harmoniously allows gardeners to place different specimens close together, maximizing the productivity of a given area. The secret to successful companion planting is choosing vegetables that balance each other and have similar environmental needs. Vegetables that compete for nutrients, sunlight, or root space make poor companions. For example, tall, heat-loving, long-season plants are complemented by short-season, ground-hugging plants or small, below-ground crops.
Tomatoes
Tomatoes are a vegetable garden favorite, but they are also heat lovers that require full sun. As such, they cannot be planted beneath other garden plants. However, the area around the base of a tomato plant is often an ideal location for shallow-rooted, shade-tolerant plants, or bite-sized root vegetables. Surround tomatoes with beets, baby carrots, garlic, green onions, sage, chives and marigolds for the best results; not only to these plants grow well in the shade provided by towering tomato plants, they seem to improve the productivity of the tomato vines.
Beets
Beets are valued for both their flavorsome roots and their leafy tops. They are well adapted to most climates and flourish when set in full sun or partial shade; however, they tend to grow best in temperate regions and flourish when planted near bok choy, broccoli, cauliflower, bush beans, cabbage or tomatoes. This mid-season plant can be set out three weeks before the expected date of the final frost. Once the young sprouts emerge, they are ready to harvest 48 to 50 days later. This opens up a small area of the garden that can then be replanted with a short-season vegetable such as radishes or lettuce.
Spacing
Companion plants can be set fairly close together, saving valuable garden space. To determine the appropriate distance between companion plants, combine the suggested spacing for each plant, then divide the total by two. For example, beets should be spaced 4 inches apart, and tomatoes should have at least 24 inches of room between them. Allow at least 16 inches between beets and tomatoes.
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Miss Chen
2018年03月25日
Capsicum annuum "Inferno Hot Peppers" are a mildly hot chili pepper that are best used fresh or pickled. The Inferno pepper plant produces an abundant yield with a long harvest time. Once peppers on the plant begin to mature, continual picking and harvesting of Inferno peppers will promote more pepper production.
Days to Maturity
Inferno hot peppers mature earlier than many other pepper plants and you can begin harvesting sooner. Seed germination to fruit maturity is around 62 days, though because the Inferno pepper plant continues to produce peppers until the first frost, the harvesting of your Inferno peppers will last four to six weeks. Planting your Inferno pepper seeds after the threat of frost in the spring will have you picking the first ripe peppers by mid August, continuing into late September.
Size
The size of an Inferno pepper is an indication that it is ready to be picked. Inferno peppers have an elongated banana shape. Mature peppers will be 6 to 8 inches long and 1 to 1.5 inches wide. The Inferno hot pepper plant grows very uniformly shaped peppers, and it will be easy to distinguish the mature fruit from immature by the large, elongated size.
Color
Using the color of any variety of pepper is one of the easiest and best ways to know when to pick it. Inferno hot peppers first turn a lime green, which fades to yellow, then can turn red on the plant. At each of these color stages, the Inferno pepper can be harvested, depending on the level of spiciness you want. At the somewhat immature stage of lime green, the pepper will be very mild. Yellow-colored Inferno peppers are at the peak of ripeness and flavor. Allowing the pepper to turn red on the plant will give you the hottest flavor.
Storage
Inferno peppers are a thick-walled, fleshy, mildly hot pepper, which makes them ideal for roasting, pickling or using fresh. Because of the thick walls, this pepper should be dried because the inner flesh of the pepper may not completely dry before developing mold or rot. Fresh-picked Inferno peppers can be refrigerated for up to two weeks, or frozen in an airtight container for two to three months, retaining its peak flavor.
Days to Maturity
Inferno hot peppers mature earlier than many other pepper plants and you can begin harvesting sooner. Seed germination to fruit maturity is around 62 days, though because the Inferno pepper plant continues to produce peppers until the first frost, the harvesting of your Inferno peppers will last four to six weeks. Planting your Inferno pepper seeds after the threat of frost in the spring will have you picking the first ripe peppers by mid August, continuing into late September.
Size
The size of an Inferno pepper is an indication that it is ready to be picked. Inferno peppers have an elongated banana shape. Mature peppers will be 6 to 8 inches long and 1 to 1.5 inches wide. The Inferno hot pepper plant grows very uniformly shaped peppers, and it will be easy to distinguish the mature fruit from immature by the large, elongated size.
Color
Using the color of any variety of pepper is one of the easiest and best ways to know when to pick it. Inferno hot peppers first turn a lime green, which fades to yellow, then can turn red on the plant. At each of these color stages, the Inferno pepper can be harvested, depending on the level of spiciness you want. At the somewhat immature stage of lime green, the pepper will be very mild. Yellow-colored Inferno peppers are at the peak of ripeness and flavor. Allowing the pepper to turn red on the plant will give you the hottest flavor.
Storage
Inferno peppers are a thick-walled, fleshy, mildly hot pepper, which makes them ideal for roasting, pickling or using fresh. Because of the thick walls, this pepper should be dried because the inner flesh of the pepper may not completely dry before developing mold or rot. Fresh-picked Inferno peppers can be refrigerated for up to two weeks, or frozen in an airtight container for two to three months, retaining its peak flavor.
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文章
Miss Chen
2018年03月24日
Many vegetables make good home crops, and the cucumber plant (Cucumis sativus) is one of the best. Usually quite productive and easy to grow, a failing cucumber plant can leave you wondering if your green thumb has turned brown. Sometimes, however, cucumbers develop but fail to turn green or start out green only to become orange or yellow. Yellowing cucumbers might signal a problem but they are sometimes a natural occurrence. Knowing the difference is the first step, followed by making some changes to prevent abnormal yellowing.
Baby I Was Born This Way
Although most cucumbers are dark green, yellow varieties do exist. The "Lemon" cultivar is a good example. Like all cucumbers, it grows as an annual in all parts of the United States. It differs from other cucumber varieties in that it produces ball-shaped, 4-inch wide cucumbers in bright yellow. Whether you start cucumber plants from seed or purchase seedlings at a nursery, check the label and know what you're growing. It's possible your cucumbers were always destined to turn yellow.
Cucumbers left on the vine too long will also turn yellow and orange as they start to fade. They may also become overly large. While you certainly won't enjoy eating these bitter vegetables, leaving them on the vine slows or stops the production of new cucumbers. It's best to remove and discard them.
Food and Water
Improper watering and fertilizing can both result in yellow cucumbers. Cukes have shallow roots that crave moisture, but leaving them with wet feet can make them turn yellow. Cucumber plants do best when watered once weekly during dry spells, or whenever the top inch of soil feels dry to the touch. A particularly rainy growing season may lead to a disappointing crop.
Adequate nutrition also helps ensure healthy green cucumbers. A lack of nutrients can cause yellowing of both the leaves and cucumbers, which may stay small rather than reaching their full size. To prevent this, mix 1 cup of a 10-10-10 granular fertilizer into each 10-foot row at planting time. When the young vines reach 1 foot in length, mix 1 tablespoon of fertilizer into the soil beside each plant.
Cucumber Mosaic Virus
Mosaics are often attractive works of art, but this is not so when it comes the cucumber mosaic virus. This disease is incurable and caused by an organism that creates a yellow, mottles appearance on the cucumber plant's leaves. It also causes small, stunted cucumbers with yellow or white mottling. Remove and destroy any plants that show signs of this virus and keep a close eye on any remaining cucumbers in your garden.
Aphids and cucumber beetles spread the cucumber mosaic virus, so controlling them is important. Early in the season, cover the plants with floating row covers. You'll need to remove the covers by early summer to allow pollination, but they will offer young plants protection early in the growing season. For pest control after you uncover the plants, spray them with insecticidal soap, diluted at a rate of 5 tablespoons of soap per gallon of water. Spray on a still, windless day and repeat every two weeks as needed.
Other Cucumber Crises
While the cucumber mosaic virus is the biggie, several other issues can cause yellow, wilted plant leaves and small cucumbers with an orange or yellow color. These include bacterial wilt and fungal problems. Striped cucumber beetles spread bacterial wilt and are best controlled with the same floating row covers used to discourage aphids. Later in the season, handpick the beetles off the plants when you see them. This is a much safer alternative than pesticides since you'll want to know your cucumbers are chemical-free and safe to eat.
Fungal disorders are best controlled by keeping air flowing through your crop. Space your plants 8 to 15 inches apart and avoiding wetting the foliage when watering. Growing plants on trellises also improves air circulation while keeping cucumbers up and off of moist soil.
If you do experience disease problems, choose disease-resistant varieties next year and try again, "Marketmore 76" and "Fanfare" are two excellent options. Rotate your planting location every two years, as well. Cucumber beetles can overwinter in your garden soil and easily find (and infect) your cucumbers again if you plant them in the same location.
Baby I Was Born This Way
Although most cucumbers are dark green, yellow varieties do exist. The "Lemon" cultivar is a good example. Like all cucumbers, it grows as an annual in all parts of the United States. It differs from other cucumber varieties in that it produces ball-shaped, 4-inch wide cucumbers in bright yellow. Whether you start cucumber plants from seed or purchase seedlings at a nursery, check the label and know what you're growing. It's possible your cucumbers were always destined to turn yellow.
Cucumbers left on the vine too long will also turn yellow and orange as they start to fade. They may also become overly large. While you certainly won't enjoy eating these bitter vegetables, leaving them on the vine slows or stops the production of new cucumbers. It's best to remove and discard them.
Food and Water
Improper watering and fertilizing can both result in yellow cucumbers. Cukes have shallow roots that crave moisture, but leaving them with wet feet can make them turn yellow. Cucumber plants do best when watered once weekly during dry spells, or whenever the top inch of soil feels dry to the touch. A particularly rainy growing season may lead to a disappointing crop.
Adequate nutrition also helps ensure healthy green cucumbers. A lack of nutrients can cause yellowing of both the leaves and cucumbers, which may stay small rather than reaching their full size. To prevent this, mix 1 cup of a 10-10-10 granular fertilizer into each 10-foot row at planting time. When the young vines reach 1 foot in length, mix 1 tablespoon of fertilizer into the soil beside each plant.
Cucumber Mosaic Virus
Mosaics are often attractive works of art, but this is not so when it comes the cucumber mosaic virus. This disease is incurable and caused by an organism that creates a yellow, mottles appearance on the cucumber plant's leaves. It also causes small, stunted cucumbers with yellow or white mottling. Remove and destroy any plants that show signs of this virus and keep a close eye on any remaining cucumbers in your garden.
Aphids and cucumber beetles spread the cucumber mosaic virus, so controlling them is important. Early in the season, cover the plants with floating row covers. You'll need to remove the covers by early summer to allow pollination, but they will offer young plants protection early in the growing season. For pest control after you uncover the plants, spray them with insecticidal soap, diluted at a rate of 5 tablespoons of soap per gallon of water. Spray on a still, windless day and repeat every two weeks as needed.
Other Cucumber Crises
While the cucumber mosaic virus is the biggie, several other issues can cause yellow, wilted plant leaves and small cucumbers with an orange or yellow color. These include bacterial wilt and fungal problems. Striped cucumber beetles spread bacterial wilt and are best controlled with the same floating row covers used to discourage aphids. Later in the season, handpick the beetles off the plants when you see them. This is a much safer alternative than pesticides since you'll want to know your cucumbers are chemical-free and safe to eat.
Fungal disorders are best controlled by keeping air flowing through your crop. Space your plants 8 to 15 inches apart and avoiding wetting the foliage when watering. Growing plants on trellises also improves air circulation while keeping cucumbers up and off of moist soil.
If you do experience disease problems, choose disease-resistant varieties next year and try again, "Marketmore 76" and "Fanfare" are two excellent options. Rotate your planting location every two years, as well. Cucumber beetles can overwinter in your garden soil and easily find (and infect) your cucumbers again if you plant them in the same location.
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文章
Miss Chen
2018年03月23日
It is entertaining to watch a cucumber (Cucumis sativus) grow through its stages from tiny vine to full-size plant with edible fruits. As the soil temperature reaches the 70 degree Fahrenheit range, it is time to plant cucumber, one of the most popular vegetables in the Cucurbitaceae family of plants. Producing fruits used for pickling, slicing or eating fresh off the vine, cucumber is a simple vegetable to grow in a home garden.
Seed Sowing and Seedling Emergence
The seeds of vining cucumber varieties such as 'Boston Pickling' and 'Lemon Cucumber' are sown either four to five seeds per hill of soil or 2 to 3 feet apart in a straight row. Seed germination, or sprouting, occurs fairly fast. Watch for the two-leaved seedlings to emerge above the soil three to 10 days after sowing the seeds.
A seedling's first two leaves are called cotyledon and are round with smooth edges. The next leaves are true leaves with the characteristic cucumber heart-shape and sharp-edged margins.
The soil should remain moist at all times as the seedlings begin to grow. To test for moistness, put your finger in the soil. It should not be dry beyond the first finger joint. As seedlings reach 4 inches in height, remove some of them so the remaining ones are 1 ½ feet apart.
Each bush variety of cucumber requires 2 to 3 square feet of space, and the vine type can reach to 6 feet in height. Trellis systems or tomato cages can be used to support plants that are the vine type.
Plant cucumber seeds every two to three weeks until three months before your area's first average annual frost date to have a continuous harvest of cucumber fruits as summer progresses.
Flowering and Pollination
Cucumbers produce two kinds of bright, golden-yellow flowers: male and female. Male flowers emerge first but do not produce fruits and fall off after pollination is complete. Female flowers emerge within one to two weeks.
Cucumber plants are not self-pollinating; they require bees or other pollinators to carry their pollen from male flowers to female flowers. Insecticides applied at cucumbers' flower stage of growth can kill the pollinators, interfering with the process of pollination.
Fruiting and Harvest
After female cucumber flowers have been pollinated, they swell at their bases and begin to develop into fruits. Cucumber fruits usually can be harvested 50 to 70 days after the seeds were sown, depending on the variety and weather conditions.
Cucumber varieties used for pickling are ready to harvest when the fruits reach 3 to 4 inches in length. The harvest lasts seven to 10 days for each of those plants. The longer fruits of varieties used for slicing are ready for harvest when they are 7 to 8 inches long, and their harvest time may continue for as long as four to six weeks.
At peak harvest time, cucumber fruits should be picked every two days. Cucumber plants produce more fruits when the fruits are picked regularly. Fruits left on the vines become bitter and their skins tough.
A mature cucumber plant produces about 5 pounds of fruits, or about 10 fruits that are each 6 ounces. Heirloom varieties, however, produce about 2 to 3 pounds of fruits per plant.
Post-Harvest
When harvest is complete, pull the cucumber vines or bushes out of the soil, and put them into the compost bin or pile. Long vines can be cut into 1-to 2-foot lengths for speedier decomposition. Vines or bushes left on the ground to decompose may attract pests or diseases to the garden.
Seed Sowing and Seedling Emergence
The seeds of vining cucumber varieties such as 'Boston Pickling' and 'Lemon Cucumber' are sown either four to five seeds per hill of soil or 2 to 3 feet apart in a straight row. Seed germination, or sprouting, occurs fairly fast. Watch for the two-leaved seedlings to emerge above the soil three to 10 days after sowing the seeds.
A seedling's first two leaves are called cotyledon and are round with smooth edges. The next leaves are true leaves with the characteristic cucumber heart-shape and sharp-edged margins.
The soil should remain moist at all times as the seedlings begin to grow. To test for moistness, put your finger in the soil. It should not be dry beyond the first finger joint. As seedlings reach 4 inches in height, remove some of them so the remaining ones are 1 ½ feet apart.
Each bush variety of cucumber requires 2 to 3 square feet of space, and the vine type can reach to 6 feet in height. Trellis systems or tomato cages can be used to support plants that are the vine type.
Plant cucumber seeds every two to three weeks until three months before your area's first average annual frost date to have a continuous harvest of cucumber fruits as summer progresses.
Flowering and Pollination
Cucumbers produce two kinds of bright, golden-yellow flowers: male and female. Male flowers emerge first but do not produce fruits and fall off after pollination is complete. Female flowers emerge within one to two weeks.
Cucumber plants are not self-pollinating; they require bees or other pollinators to carry their pollen from male flowers to female flowers. Insecticides applied at cucumbers' flower stage of growth can kill the pollinators, interfering with the process of pollination.
Fruiting and Harvest
After female cucumber flowers have been pollinated, they swell at their bases and begin to develop into fruits. Cucumber fruits usually can be harvested 50 to 70 days after the seeds were sown, depending on the variety and weather conditions.
Cucumber varieties used for pickling are ready to harvest when the fruits reach 3 to 4 inches in length. The harvest lasts seven to 10 days for each of those plants. The longer fruits of varieties used for slicing are ready for harvest when they are 7 to 8 inches long, and their harvest time may continue for as long as four to six weeks.
At peak harvest time, cucumber fruits should be picked every two days. Cucumber plants produce more fruits when the fruits are picked regularly. Fruits left on the vines become bitter and their skins tough.
A mature cucumber plant produces about 5 pounds of fruits, or about 10 fruits that are each 6 ounces. Heirloom varieties, however, produce about 2 to 3 pounds of fruits per plant.
Post-Harvest
When harvest is complete, pull the cucumber vines or bushes out of the soil, and put them into the compost bin or pile. Long vines can be cut into 1-to 2-foot lengths for speedier decomposition. Vines or bushes left on the ground to decompose may attract pests or diseases to the garden.
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文章
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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