动态第335页 - 绿手指 - 养花技巧、花生病了怎么办、花园打理和设计

2018年02月27日

Description: This perennial plant is 3-6" tall. The individual leaves and flowering stems emerge directly from the rootstock. Each leaf is deeply divided into 3-5 palmate lobes, while a lobe may be further subdivided into 2-3 smaller lobes. The lobes are usually broader toward their tips than at the base of the leaf, and their tips may have 1 or 2 small teeth. A typical leaf is about 1" long and across (excluding the petiole). The petiole of each leaf is rather long and slender. The slender flowering stems are at least as long as the petioles; they are either green or purple. Each stem curves abruptly downward near the flower. The entire plant is hairless, or nearly so. The flowers have 5 petals and 5 sepals; they are ¾–1½" across. The sepals are green, while the petals are pale blue-violet to dark purple-violet. Usually the petals are the same color, although sometimes the upper two petals are dark purple-violet, while the lower three petals are pale blue-violet. Toward the throat of the flower, the lower petal is white with fine violet lines that function as nectar guides. There are no white hairs near the throat. The stamens are a conspicuous golden yellow. The blooming period is mid- to late spring, and this plant may bloom during the fall. There may be a mild floral scent in some local ecotypes. Unlike other violets, Birdfoot Violet does not produce cleistogamous flowers. The coppery seeds can be ejected several inches from the mother plant. There is a sugary gel on the seeds that attracts ants; these ants often carry these seeds to their nests. The root system consists of a tuberous caudex with long coarse roots. Sometimes rhizomes are produced, forming vegetative offsets. Cultivation: The preference is full sun and dry conditions. However, a little shade and more moisture is tolerated, if the site is well-drained. The soil should be sandy or rocky to reduce competition from other plants; a somewhat acid pH is preferred. The greatest danger is crown rot from poorly drained, heavy soil. This plant is more difficult to grow than most. [图片]Range & Habitat: The native Birdfoot Violet occurs occasionally in northern Illinois and in counties along the Mississippi River, but it is uncommon or absent elsewhere (see Distribution Map). Habitats include upland areas of black soil prairies, sand prairies, hill prairies, sandstone glades, cherty slopes, thinly wooded bluffs, openings in rocky or sandy forests, sandy Black Oak savannas, and sand dunes near Lake Michigan. This plant is largely restricted to high quality habitats. Fire is a beneficial management tool in areas with trees and shrubs. Faunal Associations: The flowers attract long-tongued bees, small butterflies, and skippers. Bee visitors during the spring include bumblebees and Anthophorine bees. Compared to other violets, the flowers of this species attracts more butterflies and skippers, which are often held horizontal to the ground (face up) and easier for such insects to land on. The caterpillars of various Fritillary butterflies feed on the foliage and flowers; the caterpillars of Speyeria idalia (Regal Fritillary) may prefer this violet species over others as a food source. As noted above, ants are attracted to the sugary gel on the seeds, and help to distribute them. [图片]Photographic Location: The photograph of the plant with bicolored flowers was taken at a thinly wooded bluff near Kickapoo State Park in Vermilion County, Illinois. The photograph of the plant with pale blue-violet flowers was taken at a sandy savanna in Kankakee County, Illinois. The photograph of the plant with with violet flowers was taken on a sandy wooded hillside at the Indiana Dunes State Park in NW Indiana. Comments: The photographs show three different color-forms of Birdfoot Violet and they are all beautiful. This violet can be distinguished from other Viola spp. (Violets) by its deeply lobed leaves, the large size of its flowers, and the absence of hairs near the throat of each flower. The common name refers to the appearance of the leaves.

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Miss Chen

2018年02月27日

Description: This wildflower is a winter or spring annual about 6" tall, sometimes branching near the base of the plant; it is more or less erect. The small basal leaves have orbicular blades with long slender petioles; these are followed by alternate leaves along the stems. The stems are light green to purplish greenPlant in Bloom and hairless. The alternate leaves are obovate, oblanceolate, or linear-oblanceolate, becoming more narrow as they ascend the stems. They are up to 2" long, light to medium green, hairless, and smooth to slightly crenate along their margins. Leafy stipules up to 1" long occur along the stems near the bases of the leaves. These stipules have deep narrow lobes that are smooth or ciliate along their margins; they are light to medium green like the leaves. Occasionally, individual flowers are produced from axils of the upper leaves on long naked stalks. Each of these stalks is light green to dark purple and hairless, curving downward at the apex where the flower occurs. Each flower is about ½" across, consisting of 5 petals and 5 sepals. The petals are pale to medium blue-violet with dark purple lines, becoming white near the throat of the flower. However, the lowermost petal has a patch of yellow near its base. Also, the two lateral petals are bearded with white hairs near the throat of the flower. The sepals are smaller in size than the petals; they are light green to purplish green, lanceolate, and hairless. The blooming period occurs from mid-spring to early summer and lasts about 1½ months. Fertilized flowers produce seed capsules. The small seeds are light brown and globoid; they are ejected mechanically from their ripened capsules. The root system consists of a slender branching taproot. Colonies of plants are occasionally formed. Cultivation: The preference is full or partial sun, moist to mesic conditions, and a light friable soil containing some sand. However, this wildflower adapts to other kinds of soil as well. Range & Habitat: The native Field Pansy is occasional in the southern half of Illinois and uncommon or absent in the northern half of the state (see Distribution Map). Habitats include limestone glades, moist sand prairies, fields, edges of sandy paths, and waste places. Sandy areas with a history of disturbance are preferred. Faunal Associations: The nectar and pollen of the flowers attract mostly bees, although small butterflies and skippers may also visit the flowers. The caterpillars of various Fritillary butterflies (Boloria spp., Speyeria spp., etc.) and moths feed on the foliage of Viola spp. (Violets). The seeds are eaten in limited amounts by the Ruffed Grouse, Bobwhite, Wild Turkey, Mourning Dove, and some songbirds. Violets are not a preferred food source of mammalian herbivores, although rabbits and deer will browse on the foliage occasionally. [图片]Photographic Location: Edge of a sand prairie in Kankakee County, Illinois. Comments: In the past, there has been some controversy regarding whether or not the Field Pansy is native to North America as it shares many characteristics with annual Viola spp. from Eurasia. More recently, there is a growing consensus among botanists that the Field Pansy is sufficiently distinct to be considered a native species of North America. The Field Pansy is rather similar to the introduced Viola tricolor (Johnny Jump-Up). However, this latter species has larger tricolored flowers about ½–1" across and the terminal lobes of its stipules tend to have more teeth. Another introduced species, Viola arvensis (Wild Pansy), has yellow-cream flowers and its sepals are at least as long as its petals. Like the Field Pansy, these introduced species produce large stipules that are deeply lobed; this pansy-like characteristic distinguishes them from the Viola spp. that are called violets. A scientific synonym of the Field Pansy is Viola rafinesquii.

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Miss Chen

2018年02月27日

Description: This perennial plant is up to 5' tall and unbranched, except near the inflorescence. The central stem is round and smooth. Scattered along this stem are 3-7 whorled leaves. These leaves are up to 6" long and 1½" across with serrated margins. They are ovate to narrowly ovate, and are either sessile or have short petioles. At the apex of the plant are several slender spikes of white flowers up to 8" long, resembling a candelabra. The narrow tubular flowers are about ¼" long, from which 2 yellow or brown stamens are exerted. These flowers are crowded together all around each spike, blooming from the bottom up. They have no scent. The blooming period usually occurs from early to mid-summer, and lasts about a month. The tiny seeds can be carried several feet away from the mother plant by the wind. The root system consists of a central taproot and some rhizomes, which enable vegetative reproduction. Cultivation: The preference is full or partial sun, and moist to average conditions. Growth is best in rich loamy soil, although some sand or clay is tolerated. The leaves may turn yellowish green in bright sunlight or during a drought, otherwise they normally appear healthy and are not often bothered by disease. This plant has a tendency to flop over on slopes. [图片]Range & Habitat: The native Culver's Root occurs throughout Illinois, except a few south-central counties (see Distribution Map). Although widely distributed, it is only occasionally seen. Culver's root occurs in moist to mesic black soil prairies, sand prairies, openings and edges of woodlands, thickets, savannas, and swampy meadows along rivers and ditches. This plant is not often seen in highly disturbed habitats. Faunal Associations: The most common visitors to the flowers are long-tongued and short-tongued bees, which collect pollen or suck nectar. This includes honeybees, bumblebees, Mason bees, Green Metallic bees, Masked bees, and others. Other kinds of insect visitors include Sphecid wasps, butterflies, moths, and Syrphid flies. The latter include species that feed on pollen only and are non-pollinating. Culver's Root doesn't appear to be bothered by leaf-chewing insects or mammalian herbivores to the same extent as other plants. The seeds are too tiny to be of much interest to birds. [图片]Photographic Location: The photographs were taken at Meadowbrook Park in Urbana, Illinois. Comments: While in bloom, this plant has an elegant appearance, although the pretty white flowers rapidly turn brown. Its common name refers to the medicinal usage of the bitter root, which has purgative properties. The surname 'Culver' probably refers to a pioneer physician who advocated the use of this plant for the treatment of various ailments.

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Miss Chen

2018年02月27日

Description: This perennial plant is 3-6' tall and unbranched, except for the flowering stalks of the inflorescence. The central stem is stout and covered with fine white hairs. The alternate dark green leaves are up to 7" long and 2" across. They are lanceolate to narrowly ovate, and slightly serrrated along the margins. The lower sides of the leaves are covered in dense white hairs, which are longer and more prominent than other Vernonia spp. At the apex of the plant, the inflorescence is a corymb of numerous rayless composite flowers. The hairy stems of the inflorescence are usually reddish brown. Each composite flower is about ½–¾" across, and contains from 30-60 disk florets (usually closer to the lower end of the range). These florets are bright magenta and quite showy. There is no floral scent. Numerous dull green or reddish brown bracts subtend the composite flowers, which are aligned together like fish scales. The blooming period occurs from late summer to early fall, and lasts about a month. The root system is densely fibrous and rhizomatous, and will form offsets to create a small colony of plants. The ribbed, slightly hairy achenes have a small tufts of light brown hair, and are dispersed by the wind. Cultivation: This plant prefers full or partial sunlight and moist to average conditions. It is somewhat drought resistant. Under severe conditions, the plant will wilt and blooms abort. The soil texture can consist of fertile loam, clay-loam, or have a slightly gritty texture from exposed glacial till and gravel. Disease is not troublesome, except for occasional episodes of mildew during the fall. This species is easy to grow. Range & Habitat: The native Missouri Ironweed occurs throughout Illinois, except in the NW corner of the state (see Distribution Map). It is a common plant. Typical habitats include moist to mesic black soil prairies, openings and edges of woodlands, swamps, seeps, limestone glades, edges of lakes, overgrazed pastures, vacant lots, and areas along railroads. It is common in disturbed areas, but also occurs in high quality habitats. [图片]Faunal Associations: The flowers attract long-tongued bees, butterflies, and skippers primarily. Among the bees, are such visitors as bumblebees, Epeoline Cuckoo bees, and Miner bees. Butterfly visitors include Swallowtails, Whites, Sulfurs, Monarchs, Painted Ladies, and others. Bee flies and Halictid bees may also visit the flowers. The flowers are capable of self-pollination in the absence of these insects. The caterpillars of some moths feed on Ironweed species, including Grammia parthenice (Parthenice Tiger Moth), Perigea xanthioides (Red Groundling), and Papaipema cerussata (Ironweed Borer Moth). Mammalian herbivores avoid consumption of this plant because of the bitter taste of the leaves. In overgrazed pastures, Ironweed is an 'increaser' because it is one of the last plants to be eaten. [图片]Photographic Location: Photographs were taken at the Red Bison Railroad Prairie in Savoy, Illinois. Comments: This is an attractive plant when in bloom, and one of the best attractors of late summer butterflies. Missouri Ironweed can be distinguished from other Vernonia spp. primarily by the number of disk florets in the compound flowers, and the profuse hairiness of the stems and lower sides of the leaves. It is probably the most common species of ironweed in Illinois. Sometimes hybrids occur among different species of ironweeds, making identification difficult.

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Miss Chen

2018年02月27日

Description: This herbaceous perennial plant is 2-4' tall and unbranched. The central stem is round, hairless, and white, light green, or reddish purple. The alternate leaves are up to 5" long and ½" across. They are narrowly lanceolate, narrowly ovate, or linear. Their margins are serrated, while the upper and lower leaf surfaces are hairless. The lower leaf surface also has a prominent central vein, and black dots may be present. The leaves are sessile against the stem, or they have short petioles. The central stem terminates in a flat-topped cluster of magenta compound flowers (i.e., a corymb). This flower cluster is quite dense, rather than loose and spreading. The flowering stalks may be slightly pubescent. A compound flower consists of 15-30 disk florets with a short cylinder of green bracts underneath. These bracts are appressed together like fish scales, and they are often slightly ciliate. The cylinder of bracts spans about 1/5" across. A disk floret is magenta, with 5 spreading lobes and a prominent divided style. The blooming period occurs from late summer to early fall, and lasts about a month. There is no noticeable floral scent. The flowers are replaced by achenes that have a pappus of hair-like scales. These achenes can be blown several feet from the mother plant by gusts of wind. The root system is spreading and fibrous. Cultivation: The preference is full sun, moist conditions, and fertile soil. Partial sun and slightly moister or drier conditions are also tolerated. This plant can withstand occasional flooding for short periods of time. The foliage is not bothered by pests and disease to any significant extent. [图片]Range & Habitat: The native Smooth Ironweed is fairly common in in the northern half of Illinois, but uncommon elsewhere in the state (see Distribution Map). Habitats include wet to moist black soil prairies, riverbottom prairies, marshes, sloughs along railroads, and edges of fields. Smooth Ironweed is found in wetland habitats to a greater extent than other species of Ironweeds. Faunal Associations: The flowers attract long-tongued bees, butterflies, and skippers primarily. Other visitors include bee flies and Halictid bees. These insects seek nectar, although bees also collect pollen. Among the long-tongued bees, are such visitors as bumblebees, Epeoline cuckoo bees, Miner bees, and large Leaf-Cutting bees. An oligolectic bee of Ironweeds is Melissodes vernoniae. The caterpillars of several moths feed on Ironweed, including Grammia parthenice (Parthenice Tiger Moth) and Perigea xanthioides (Red Groundling). Caterpillars that bore into the roots or stems of Ironweed include Papaipema cerussata (Ironweed Borer Moth), Carmenta bassiformis (Eupatorium Borer Moth), and some Polygrammodes spp. (Pyralid Moths). The bitter foliage of Ironweed deters consumption by mamamalian herbivores – it is known as an 'increaser' because it is one of the last plants to be eaten in overgrazed pastures. [图片]Photographic Location: The photographs were taken of plants growing in a moist prairie along a railroad in Iroquois County, Illinois. Comments: Another common name for this plant is Common Ironweed. However, in southern Illinois, this species is not common. Smooth Ironweed is one of the smaller Ironweeds with a compact inflorescence and smooth hairless leaves. Other Ironweed species have hairy stems or leaves. An exception is Vernonia gigantea (Tall Ironweed), which has hairless leaves and stems upon occasion. However, Tall Ironweed has a spreading inflorescence, and it is usually a taller plant (as the name implies). The larger leaves of Tall Ironweed exceed ½" across, while the leaves of Smooth Ironweed are ½" or less. Some authorities state that Smooth Ironweed has black dots on the undersides of the leaves, but this is not always true. The species in this genus are occasionally difficult to identify because they can hybridize with each other.

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Miss Chen

2018年02月26日

Description: This perennial plant is 2½–5' tall and unbranched, except near the inflorescence at the apex. The stout central stem is covered with fine white hairs that are quite short. It may have some light purple coloration in some areas. The alternate leaves are up to 5" long and 2" across. They are lanceolate or lanceolate-ovate with serrated margins. Their green upper surface is rough-textured, while the lower surface is finely pubescent with some short white hairs on the major veins. The leaves are short-petioled or sessile against the stem. At the apex of the plant is a loose cluster of flowerheads that is more or less flattened on top. Each flowerhead has 15-30 magenta disk florets and no ray florets. At the base of the flowerhead, are numerous green bracts with recurved tips (i.e., they have a tendency to curl outward). A disk floret has 5 narrow lobes that spread outward, and a prominent divided style. The tips of the style often curl back to form a pair of small coils. The blooming period is mid- to late summer, and lasts about a month. There is no floral scent. The disk florets are replaced by bristly achenes that are flat and oblong. The root system is coarsely fibrous and produces rhizomes, which enable the vegetative spread of this plant. Cultivation: The preference is full or partial sun and mesic to dry conditions. This plant is not particular about soil type; it often grows in soil that contains clay or abundant rocky material. This species of Ironweed is more drought-resistant than other species in the genus. It blooms a little earlier as well. Range & Habitat: The native Baldwin's Ironweed is an occasional plant in southwest Illinois, and it is rare or absent elsewhere (see Distribution Map). This plant is more common in states that lie southwest of Illinois (e.g., Missouri). Habitats include upland areas of dry prairies, hill prairies, glades, openings in upland forests, thinly wooded rocky slopes, pastures, abandoned fields, areas along railroads, and miscellaneous waste areas. [图片]Faunal Associations: Primarily long-tongued bees, butterflies, and skippers visit the flowers for nectar. Short-tongued bees may collect pollen from the flowers, but they are non-pollinating. Among the bees, are such visitors as bumblebees, Epeoline Cuckoo bees, and Miner bees. Among the butterfly visitors, Swallowtail and Sulfur butterflies are particularly prominent. The caterpillars of some moth species feed on various parts of Ironweed, including Grammia parthenice (Parthenice Tiger Moth), Perigea xanthioides (Red Groundling), and Papaipema cerussata (Ironweed Borer Moth). Mammalian herbivores generally avoid eating the foliage of Ironweed spp. because of its bitter taste. In pastures, Ironweeds tend to increase at the expense of other plants. Photographic Location: The photographs were taken of a small colony of plants growing in a prairie at Meadowbrook Park in Urbana, Illinois, where this species was undoubtedly introduced. [图片]Comments: Baldwin's Ironweed is one of the less common species of Ironweed in Illinois. It is a sturdy plant that is well-adapted to dry prairies. The most distinctive characteristic of Baldwin's Ironweed is the recurved tips of its involucral bracts; this sets it apart from other Ironweed spp. in Illinois, which have appressed bracts. However, there is a less common variety of Baldwin's Ironweed that also has appressed bracts at the base of the flowerheads. Baldwin's Ironweed can be distinguished from Vernonia missurica (Missouri Ironweed) by counting the number of disk florets in a flowerhead – Baldwin's Ironweed has 15-30 disk florets, while Missouri Ironweed has 30-55 disk florets. With respect to Vernonia gigantea (Tall Ironweed), Baldwin's Ironweed is a stouter plant with broader leaves. Finally, the stems and leaf undersides of Baldwin's Ironweed are pubescent, while Vernonia fasciculata (Smooth Ironweed) is glabrous throughout. Sometimes, different species of Ironweed hybridize with each other, making identification difficult. Another common name for Vernonia baldwinii is Western Ironweed.

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Miss Chen

2018年02月26日

Description: This perennial plant is 2½–5' tall and unbranched, except near the apex where the inflorescence occurs. The central stem is light green, terete, slightly short-pubescent, and stiffly erect. Alternate leaves occur along the entire length of the stem; they are ascending to widely spreading. The leaves are 3-6" long and ¼–¾" across; they are linear to linear-elliptic in shape, sessile or short-petiolate, and either entire (toothless) or sparsely and minutely toothed along their margins. The leaves have prominent central veins that are light-colored. The upper leaf surface is medium to dark green and glabrous to rough-textured from minute stiff hairs. The lower leaf surface is light green and glabrous to sparsely short-pubescent, except along central vein, where it is pubescent. The central stem and lateral upper stems terminate in clusters of flowerheads that are somewhat flat-topped. The branches and peduncles of the flowerheads are light green, sparsely short-pubescent, and terete; the peduncles are 1½–5" long. Flowerheads Each flowerhead is ¾–1¼" across, consisting of a dense head of 50-100 disk florets and no ray florets. The corollas of the disk florets are magenta (reddish purple), narrowly tubular in shape, and 5-lobed; the corolla lobes of these florets are narrowly lanceolate in shape and ascending. Bifurcated styles are exserted from these corollas; these styles are magenta. Surrounding the base of each flowerhead, there are numerous phyllaries in several series; they are loosely overlapping. Individual phyllaries are ½–1" long; their bases are linear-lanceolate in shape, tapering into long filiform tips that are more or less incurved. These phyllaries are mostly light green, except toward their tips, where they are often white to magenta; they are sparsely short-pubescent. The blooming period occurs from late summer to early autumn, lasting about 1 month for a colony of plants. There is no noticeable floral scent. Afterwards, the florets are replaced by achenes with small tufts of bristly hair at their apices; these hairs are light brown or pale purple. The achenes are 3-5 mm. long and bullet-shaped with vertical pubescent ribs; they are distributed to some extent by the wind. The root system consists of stout short rhizomes, from which clonal offsets are produced. [图片]Cultivation: In Illinois, this plant occurs at sites with full sun, mesic conditions, and a loam or clay-loam soil. Range & Habitat: Great Ironweed is a very rare plant in Illinois; it has been collected only in Champaign County in the east-central portion of the state during 1957-1958 (see Distribution Map). These specimens are located in the herbarium of the Illinois State Museum. Apparently, the population of plants at the original collection site was destroyed and the species was thought to be extirpated from the state. However, during the late summer of 2005 the webmaster discovered several plants of Great Ironweed at Meadowbrook Park in Urbana, Illinois (also in Champaign County). The status of this ironweed as a native or adventive species in Illinois is uncertain. Habitats of this rare species in Champaign County include roadside fencerows and prairies. Great Ironweed is more common in areas that lie to the southwest of Illinois (e.g., Missouri and Arkansas). It is often found in rocky glades in these areas. [图片]Faunal Associations: The flowerheads of ironweeds (Vernonia spp.) attract bumblebees, little carpenter bees (Ceratina spp.), cuckoo bees (Triepeolus spp.), digger bees (Melissodes spp., Svastra spp.), leaf-cutting bees (Megachile spp.), Halictid bees (including green metallic bees), bee flies (Bombyliidae), butterflies (Papilio spp. & others), and skippers (Polites spp. & others); see Robertson (1929) and Reed (1993). The bee visitors are attracted to the nectar and pollen of the flowerheads, while the remaining insects feed on the nectar. Two digger bees, Melissodes vernoniae and Melissodes denticulata, are specialist pollinators (oligoleges) of ironweeds. Other insects feed on the leaves, bore through the stems or roots, suck plant juices, or feed destructively on the flowerheads of these plants. Examples of such insects include the Thirteen-spotted Billbug (Rhodobaenus tredecimpunctatus), larvae of the Ironweed Bud Midge (Asphondylia vernoniae), larvae of the Ironweed Blossum Midge (Youngomyia podophyllae), larvae of the Ironweed Borer Moth (Papaipema cerussata), larvae of the Parthenice Tiger Moth (Grammia parthenice), the Ironweed Aphid (Aphis vernoniae), Four-humped Stink Bug (Brochymena quadripustulata), Little Pasture Grasshopper (Melanoplus confusus), Four-spotted Tree Cricket (Oecanthus quadripunctatus), and Short-winged Meadow Katydid (Conocephalus brevipennis). The Insect Table provides a more complete list of insects that feed on ironweeds. Vertebrate animals appear to have little use for these plants, as their seeds are little-used by birds and their bitter foliage is usually avoided by mammalian herbivores. [图片]Photographic Location: A prairie at Meadowbrook Park in Urbana, Illinois, where a population of this ironweed has persisted for several years. Comments: This is one of the easier ironweeds (Vernonia spp.) to identify because of the distinctive appearance of the phyllaries (floral bracts) – long and thread-like. No other ironweed has this kind of phyllary at the base of its flowerheads. Great Ironweed (Vernonia arkansana) also differs from other ironweeds by its narrow leaves and the large number of disk florets (50-100) in each flowerhead. Other species in this genus have flowerheads with fewer disk florets (20-50) and their flowerheads are less wide. Other common names of Vernonia arkansana that are occasionally used include 'Ozark Ironweed' and 'Curlytop Ironweed.' An alternative scientific name for this species is Vernonia crinita. I am happy to see this wonderful wildflower back in the state again.

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Miss Chen

2018年02月26日

Description: This perennial plant is unbranched and about 3-4' tall. The central stem is winged, with a slight scattering of small white hairs on the ridges. The alternate leaves are about 5" long and 2" wide, lanceolate to ovate in shape, rather soft in texture, and covered with small white hairs. This gives the leaves a fuzzy light green appearance, especially on their undersides. [图片]The inflorescence at the apex of the plant has several daisy-like composite flowers on rather short pedicels with abundant long white hairs. These composite flowers are bright yellow, about 2–2½" across, and become rather ragged in appearance after they pass their prime. Each flower has 6-12 ray florets, which spread outward horizontally from the central cone (roughly), rather than drooping. The disk florets present a pincushion-like appearance, with each disk floret projecting outward and visibly separated from the others. The blooming period is early to mid-summer, and lasts about a month. There is no noticeable scent to the flowers. This plant often forms colonies from its rhizomes. Cultivation: The preference is full to partial sun, and mesic conditions. During a drought this plant sometimes wilts, but recovers readily after significant rainfall. This plant often flourishes in soil that is loamy, and will tolerate some clay or stones. The foliage is rarely bothered by disease.Close-up of Leaves Range & Habitat: The native Yellow Crownbeard occurs occasionally in the southern 3/5 of Illinois, from Peoria to Champaign-Urbana, and southward. It is apparently absent elsewhere (see Distribution Map). It occurs in mesic black soil prairies, rocky upland forests, savannas, thickets, limestone glades, and along railroads. It is especially likely to be observed along railroad prairies. Faunal Associations: Primarily long-tongued bees visit the flowers for pollen or nectar. These include bumblebees, honeybees, large Leaf-Cutting bees, Little Carpenter bees, and various Cuckoo bees. Other visitors include Halictine bees, Dagger bees, and Thread-Waisted wasps. The caterpillars of the butterfly Chlosyne nycteis (Silvery Checkerspot) and Basilodes pepita (Gold Moth) feed on the foliage. Photographic Location: The photographs were taken at the Red Bison Railroad Prairie in Savoy, Illinois. Comments: This is an attractive plant because of the fuzzy leaves; the composite flowers are an additional bonus. Yellow Crownbeard, along with other members of the genus, has been oddly neglected in many prairie field guides, even though it clearly occurs in tallgrass prairies. Nor is it easy to obtain seed or plants from nursuries that specialize in native wildflowers, possibly because of the more southern distribution of this species. Another member of this genus that sometimes occurs in prairies in Illinois, Verbesina alternifolia (Wingstem), is a taller plant that blooms later. It has long coarse leaves that are sandpapery, rather than soft and fuzzy, and its ray florets droop around the central cone of each flower. A scientific synonym of Yellow Crownbeard is Actinomeris helianthoides.

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Miss Chen

2018年02月26日

Description: This short-lived perennial plant is up to 3½' tall, branching occasionally. The stems are light green to dull reddish purple and they are heavily covered with long white hairs. The opposite leaves are up to 4" long and 3" across; they are oval-ovate or obovate and coarsely serrated along the margins. The whitish green leaves are covered with fine white hairs (especially on their lower sides), and they are either sessile or have short petioles. In addition to the pinnate venation, each leaf has a reticulated network of smaller veins. The upper stems terminate in hairy floral spikes. These spikes are 1-8" long and densely crowded with pink or lavender flowers (usually the latter). The floral spikes bloom from the bottom up; relatively few flowers are in bloom at the same time. Each flower is about ¼" across or a little wider, consisting of a short corolla with a narrow opening and 5 spreading lobes, a small calyx with narrow teeth, and the reproductive organs. The calyx is grayish green to reddish purple and hairy. There is no floral scent. The blooming period occurs from mid- to late summer, and lasts about 1½ months. Four brown nutlets are produced per flower. The root system consists of a taproot, which may tiller from the base (sending up multiple stems). This plant reproduces by reseeding itself. [图片]Cultivation: The preference is full sun and mesic to dry conditions. Generally, Hoary Vervain flourishes in poor soil containing some clay, sand, or gravel. In rich loamy soil, it will grow well, but has difficulty competing with other plants. Drought resistance is good, although some of the lower leaves may shrivel and fall off the plant. The seeds germinate readily in open areas where there is some exposure to sunlight. Range & Habitat: The native Hoary Vervain occurs in almost every county of Illinois. It is fairly common, although possibly less so than in the past (see Distribution Map). Habitats include upland prairies, gravel prairies, hill prairies, barrens with stunted shrubby vegetation, limestone glades, overgrazed pastures, abandoned fields, the grassy shoulders of highway overpasses, and areas along railroads. Hoary Vervain favors low grassy areas with a history of disturbance, particularly from grazing. [图片]Faunal Associations: Many kinds of insects are attracted to the flowers, including long-tongued bees, green metallic bees, thread-waisted wasps, bee flies, thick-headed flies, butterflies, and skippers. Among the long-tongued bees, the flowers attract such visitors as honeybees, bumblebees, little carpenter bees, cuckoo bees (Triepeolus spp.), miner bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.). A specialist visitor of the flowers is Calliopsis verbenae (Verbena Bee). Several grasshoppers feed on the foliage of Hoary Vervain: Hippiscus ocelote (Wrinkled Grasshopper), Melanoplus confusus (Little Pasture Grasshopper), Melanoplus femurrubrum (Red-Legged Grasshopper), and Melanoplus keeleri luridus (Keeler's Grasshopper). Other insect feeders include caterpillars of the moth Catabena lineolata (Fine-Lined Sallow), caterpillars of Crambodes talidiformis (Verbena Moth), and the aphid Macrosiphum verbenae. The seeds of Verbena spp. are eaten by various songbirds to a limited extent, including the Cardinal (winter), Slate-Colored Junco (winter), Field Sparrow, and others. It is possible that these birds help to distribute the seeds to new areas. Mammalian herbivores rarely eat Hoary Vervain because the foliage is quite hairy and bitter. It is considered an 'increaser' in overgrazed pastures. Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois. Comments: Among the Verbena spp. that are native to Illinois, Hoary Vervain is one of the showiest, even though it is sometimes considered an unwelcome weed in pastures. This vervain can be distinguished from similar species by its larger flowers and exceptionally hairy stems and leaves. Naturally occurring hybrids of Hoary Vervain with other Verbena spp. can occur, although they are relatively uncommon.

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Miss Chen

2018年02月26日

Description: This herbaceous perennial wildflower is ¾-2½' tall and ascending to erect. It often branches near the base, while above it is unbranched or sparingly branched. The stems are glabrous or short-pubescent; pairs of opposite leaves occur at intervals along these stems. The narrow leaves are 1¼–4" long and less than ½" across; they are narrowly oblanceolate or narrowly elliptic in shape and smooth to coarsely toothed along their margins. There are more teeth toward the tips of the leaves than at their bases. The leaves taper gradually into petiole-like bases. Their upper surfaces are pale to medium green and glabrous or sparsely short-pubescent. The stems terminate into spike-like racemes of flowers about 4-12" long; there is only one raceme per stem. Only a few flowers bloom at the same time, beginning at the bottom and ending at the top of each raceme. Individual flowers are up to ¼" across, consisting of a lavender to nearly white corolla with 5 spreading lobes, a short tubular calyx with 5 teeth, 4 inserted stamens, and a pistil with a single style. At the base of each flower, there is a lanceolate leafy bract that is about the same length or a little shorter than the calyx. The blooming period occurs during the summer for about 2 months. Afterwards, the flowers are replaced by nutlets (4 per flower). These nutlets are oblongloid, somewhat flattened, and about 1/8" long. Cultivation: The preference consists of full sun, dry-mesic to dry conditions, and gravelly alkaline soil. Sandy soil is also acceptable if it isn't too acidic. Range & Habitat: The native Narrow-Leaved Vervain is occasional throughout Illinois. Habitats include dry gravel prairies and dolomite prairies, hill prairies, limestone glades, gravelly areas along railroads and roadsides, abandoned fields, and barren waste areas. This species prefers sunny areas with scant vegetation. Faunal Associations: The flowers attract bees, skippers, and probably butterflies. Robertson (1929) observed little carpenter bees (Ceratina sp.), cuckoo bees (Epeolus sp., Coelioxys sp.), leaf-cutting bees (Megachile sp.), green metallic bees (Augochlorella sp.), and the Silver-Spotted Skipper (Epargyreus clarus) visiting the flowers for nectar. Two oligophagous insects, Crambodes talidiformis (Verbena Moth) and Macrosiphum verbenae (Verbena Aphid), feed on Verbena spp. The seeds are a minor food source for the Lark Bunting (in the Great Plains) and several native sparrows that prefer open habitat. Photographic Location: A prairie in Fayette County, Illinois. The photograph of the blooming plant was taken by Keith & Patty Horn (Copyright © 2009). Comments: Narrow-Leaved Vervain can be distinguished from other Verbena spp. by its narrow leaves (less than ½" across) and long slender spikes of flowers (actually, spike-like racemes because the flowers have short pedicels). Its flowers are smaller in size than those of Verbena stricta (Hoary Vervain), but larger in size than other Verbena spp. within the state. This comparison excludes Rose Vervain, which has been reassigned to a different genus (Glandularia). Narrow-Leaved Vervain can form hybrids with other species in its genus. Two of these hybrids have been found within the state: Verbena × blanchardii (with Verbena hastata) and Verbena × moechina (with Verbena stricta).

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