绿手指
首页
动态
文章
百科
花园
设置
简体中文
已关注
+
关注
花园 (4)
动态 (4985)
Miss Chen
2018年03月29日
Miss Chen
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.
0
0
文章
Miss Chen
2018年03月29日
Miss Chen
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.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This perennial herbaceous wildflower is 1-3' tall and semi-erect to erect in habit. Its stems are light green to purplish brown, angular or terete, glabrous, and sometimes glaucous. Alternate compound leaves occur along these stems at intervals; they are widely spreading to ascending and evenly pinnate. Each compound leaf consists of 4-10 pairs of leaflets along a rachis (central stalk) that is light green to purplish brown and glabrous. The tip of each compound leaf terminates in a branched tendril that can cling to adjacent vegetation, fences, and other objects.
Individual leaflets are 1-2" long and ½-1¼" across; they are oval-ovate in shape, smooth along their margins, and glabrous. The upper leaflet surface is medium green, while the lower surface is pale green. Each leaflet has a short narrow petiole at its base that connects to the rachis of the compound leaf. Where each compound leaf joins the stem, there is a pair of leafy stipules about ½-1" in length. Each stipule is half-cordate in shape, forming a rounded basal lobe, where there are 1-3 small secondary lobes with blunt tips. Narrow racemes of 5-12 flowers (about 2½-5" in length) are borne on long naked peduncles that are shorter than the compound leaves. Individual flowers are ½-¾" long, consisting of 5 white or cream-colored petals, a light green to nearly white tubular calyx with 5 teeth, several hidden stamens, and a pistil with a single style. Each flower has aDistribution Map typical pea-like floral structure, where one upper petal forms the banner (or standard), 2 lateral petals form the wings, and 2 petals form the keel that is enclosed by the wings. The pedicels of the flowers are short and narrow. The blooming period occurs from late spring to mid-summer. Each flower is replaced by a 2-valved seedpod that becomes 2-3" long at maturity. Each seedpod is cylindrical, somewhat flattened, and glabrous, tapering at its tip into a curved beak. When they are fully mature, the seedpods divide into 2 parts to release their seeds. The root system is fibrous and rhizomatous. Cultivation: The preference is partial sun, moist to dry conditions, sandy or rocky soil with some organic matter, and relatively cool temperatures during the summer. Range & Habitat: Pale Vetchling is native to Illinois, where it is uncommon and state-listed as 'threatened.' It is found primarily in northern Illinois, although there are a few isolated populations in the southern part of the state. This wildflower is more common in areas lying north of the state. Habitats include upland woodlands, upland savannas, sandy bluffs, wooded slopes, the slopes of rocky ravines, and riverbanks. In Illinois, Pale Vetchling often occurs where oak trees are dominant. Faunal Associations: The flowers are pollinated by bumblebees and other long-tongued bees, where they seek nectar and pollen. The caterpillars of the butterfly Glaucopsyche lygdamus (Silvery Blue) sometimes feed on vetchlings (Lathyrus spp.), although they are more often found on Vetches (Vicia spp.); this insect has a boreal range that is similar to Pale Vetchling. An aphid, Nearctaphis crataegifoliae, and other aphids may feed on this plant as well. The Ruffed Grouse sometimes eats the seeds and foliage of vetchlings. Photographic Location: A woodland in NE Illinois. The photograph was taken by Tobin Fraley (Copyright © 2010). Comments: Pale Vetchling is one of several Lathyrus spp. (vetchlings) in Illinois. Sometimes it is referred to as 'Cream Pea' or 'Cream Peavine.' This species can be distinguished from others in this genus by its white or cream-colored flowers, relatively broad leaflets, and distinctive stipules, which have rounded basal lobes with one or more secondary lobes. Other species in this genus often have purple-lavender flowers, narrow leaflets (less than one-third as wide as long), and their stipules lack secondary lobes. Pale Vetchling would probably be adaptable to cultivation in partially shaded gardens.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This biennial wildflower forms a low rosette of leaves about 8-12" across during the first year. During the second year, it bolts and becomes 2-7' tall. Usually, this wildflower is unbranched, although sometimes ascending lateral branches develop along the upper one-third of a large plant. The central stem (and any lateral stems) is rather stout, terete, and light green to pale purple; it is usually hairy along the lower half of its length, becoming hairless and slightly glaucous along the upper half. The alternate leaves are up to 6" long and 2" across, becoming gradually smaller as they ascend the stem; they are pinnatifid with pointed irregular lobes and dentate along their margins. The upper surfaces of these leaves are medium green and often sparsely hairy; their lower surfaces are pale green and hairy, particularly along the midribs. The basal leaves are similar to the alternate leaves, except they tend to be larger in size and more wide toward their tips (narrowly obovate to obovate). Young developing basal leaves are usually very hairy on both their upper and lower surfaces. The central stem (and any lateral stems) terminates in an elongated panicle of flowerheads about 6-12" long and 2-4" across. The branches of the panicle are light green to reddish purple, terete, and usually hairless. Each flowerhead is about 1/3" (8-10 mm.) across when fully open, consisting of 12-25 ray florets, no disk florets, and light green to purple floral bracts that are arranged in about 3 series around its base (involucre); this base is about 2/3–3/4" (15-20 mm.) long. The rays of the flowerhead are colored salmon to brick-red and their tips are truncate and finely toothed. The outer floral bracts are shorter than the inner floral bracts.
The blooming period occurs from mid-summer to early fall and usually lasts about 3 weeks. Individual flowerheads last only a single day, blooming for only a few hours on sunny days. After only a short period of time, individual flowerheads are replaced by small black achenes with tufts of white hair. Each achene is 4-5 mm. long, ellipsoid-oblanceoloid in shape, and flattened; the tuft of white hairs is attached to the achene by a slender white beak about 2.5–3.5 mm. long. These achenes are distributed by the wind. The root system consists of a taproot. This wildflower reproduces by reseeding itself. Cultivation: The preference is partial sun, mesic to dry conditions, and somewhat acidic sandy or rocky soil. The size of individual plants is highly variable, depending on moisture levels and soil fertility.
Range & Habitat: Red-Flowered Wild Lettuce is a rare native plant in Illinois and it is state-listed as 'endangered.' Thus far, this species has been collected from a single county in southern Illinois (see Distribution Map). Because this species can be confused with other Lactuca spp., it may occur in other areas of the state. Outside of Illinois, this species is also uncommon. Habitats include upland rocky woodlands, woodland openings, woodland borders, upland savannas, sandstone glades, pastures, and abandoned fields. These habitats also include sandy areas. Red-Flowered Wild Lettuce prefers some disturbance to reduce the abundance of woody vegetation.
Faunal Associations: Little is known about floral-faunal relationships for this particular species. The flowerheads are probably cross-pollinated by various bees (medium- to small-sized), which offer nectar and pollen. In general, the caterpillars of some moths feed on Lactuca spp. (Wild Lettuce species), including Autographa precationis (Common Looper Moth), Grammia virgo (Virgin Tiger Moth), and Cucullia intermedia (Intermediate Cucullia). The caterpillars of the last moth species feed on the flowerheads. Other insect feeders include Thrips physapus (Dandelion Thrips) and several aphid species: Hyperomyza lactucae (Currant-Sowthistle Aphid), Nasonovia ribisnigri (Currant-Lettuce Aphid), Pemphigus bursarius (Lettuce Root Aphid), Prociphilus erigeronensis (White Aster Root Aphid), Uroleucon ambrosiae (Brown Ambrosia Aphid), Uroleucon gravicorne (Aphid sp.), Uroleucon pseudambrosiae (False Ambrosia Aphid), Uroleucon rudbeckiae (Golden Glow Aphid), and Uroleucon sonchella (Sowthistle Aphid). Among vertebrate animals, the Eastern Goldfinch eats the seeds, while White-Tailed Deer occasionally graze on the foliage of Lactuca spp. Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: This unusual species has been sadly neglected from many wildflower field guides. Although it has an extensive range in the eastern half of the United States, Red-Flowered Wild Lettuce appears to be uncommon to rare in most areas. The preceding description applies to var. sanguinea, rather the typical variety. In other areas of its range, Lactuca hirsuta may have yellow flowerheads and the hairiness of its stems and leaves can be variable (from nearly hairless to very hairy). Red-Flowered Wild Lettuce can be easily confused with the more common Lactuca canadensis (Common Wild Lettuce), which is itself a rather variable species. Generally, Common Wild Lettuce has flowerheads that are pale yellow to dull orange, flowerheads with shorter bases (involucres) that are ½" or less, and shorter achenes (less than 4 mm. long). Common Wild Lettuce is usually completely glabrous (except for some hairs along the lower midribs of its leaves), and its upper stems and floral branches are usually less purple. Another species, Lactuca biennis (Tall Blue Lettuce), has light blue to cream-colored flowerheads and its achenes have shorter beaks and tufts of tawny or gray hair, rather than white hair. These different Lactuca spp. cannot be identified reliably unless the flowerheads or tufted achenes are available for examination. Another common name of Lactuca hirsuta is Hairy Wild Lettuce.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This perennial wildflower consists of a rosette of basal leaves, from which a flowering stalk about 1-2' tall is produced. The basal leaves are up to 7" long and 2" across; they are pale green to green, hairless, and oblanceolate or obovate in shape. Their margins are smooth, undulate, slightly dentate, or slightly pinnatifid. The flowering stalk is pale green, hairless, glaucous, terete, and erect. There are 1-2 cauline leaves on the flowering stalk that are ovate in shape and smooth or dentate along their margins. Where the uppermost cauline leaf occurs, the stalk branches into 2-5 ascending peduncles. Each peduncle terminates in a yellow or orange-yellow flowerhead about 1–1½" across. Each flowerhead has many spreading ray florets and no disk florets. Each ray floret is narrowly oblong and yellow or orange-yellow; it has a truncate tip with 5 small teeth. The base of the flowerhead is surrounded by several floral bracts in a single series; each bract is pale green, linear-lanceolate, hairless, glaucous, and about 1/3" (8 mm.) in length or a little longer. The blooming period can occur from late spring to mid-summer and lasts about a month. Later in the year, the ray florets are replaced by small achenes. Each achene is bullet-shaped and truncate at the apex, where it has a tuft of white hairs. The achenes are distributed by the wind. The root system consists of a thickened crown with fibrous roots.
Cultivation: The preference is partial or dappled sunlight and mesic to dry conditions. Different kinds of soil are tolerated, including those containing loam, clay-loam, sand, or rocky material. Water-logged sites should be avoided. Range & Habitat: The native Two-Flowered Cynthia is occasional to locally common throughout Illinois (see Distribution Map). Habitats include open upland woodlands, open sandy woodlands, savannas and sandy savannas, rocky wooded slopes, thinly wooded bluffs, areas along woodland paths, rocky glades, and upland meadows. Two-Flowered Cynthia is often found in upland habitats where Oaks are dominant in areas with thin leaf cover and sparse ground vegetation. Faunal Associations: The flowerheads attract long-tongued bees (bumblebees, honeybees, Little Carpenter bees, Cuckoo bees, Mason bees), short-tongued bees (Halictid bees, Masked bees), predatory wasps, flies (Syrphid, Tachinid, & others), butterflies, skippers, and beetles. These insects suck nectar, collect pollen, or feed on pollen from the flowerheads. An oligolectic visitor, Andrena krigiana (Krigia Andrenid Bee), is specifically attracted to the flowerheads of Krigia spp. In addition to these floral visitors, an aphid, Uroleucon brachychaetum, sucks plant juices from these plants. Thus far, I have not observed any evidence that White-Tailed Deer feed on the foliage of Two-Flowered Cynthia, which contains a bitter white latex, although I would not rule out this possibility. Photographic Location: The photographs were taken along the edge of two wooded bluffs in Vermilion County, Illinois. Comments: The flowerheads and foliage of this wildflower are quite attractive. Most members of the Aster family with dandelion-like flowerheads (including other Krigia spp. in Illinois) have yellow ray florets, but the ray florets of Two-Flowered Cynthia often have an orange tint. Two-Flowered Cynthia has larger flowerheads (1" across or more), longer floral bracts (1/3" or more), and its achenes have more bristly hairs (20 or more) than either Krigia virginica or Krigia caespitosa (both annuals). Another species, Krigia dandelion (Potato Dandelion) has unbranched flowering stalks that each produce a single flowerhead. In contrast, Two-Flowered Cynthia has flowering stalks that branch above their uppermost cauline leaves, each stalk producing 2-5 flowerheads on separate peduncles.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
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.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This perennial wildflower is ½–1½' tall, sending up one or more unbranched leafy stems from the root system. These stems are erect, ascending, or sprawling; they are light green, tan, or reddish brown, terete, and canescent. Along each stem, there are densely spaced alternate leaves that appear to be whorled (pointing in all directions). Individual leaves are ¾–1½" long and 1/8" (3 mm.) across; they are linear in shape, smooth along their margins, stiff, and sessile (or nearly so). The upper surfaces of the leaves are medium to dark green and glabrous, while their lower surfaces are pale green and canescent. Each leaf has a prominent midvein.
The central stem terminates in a small cluster of flowerheads (sometimes only a single flowerhead is produced, but there are usually more). Individual flowerheads are born on unbranched peduncles about ½–2" long (rarely, they are longer). Along each peduncle, there are small bracts up to ¼" long that resemble the leaves, except they are much smaller in size. The daisy-like flowerheads span ¾–1¼" across, consisting of 10-20 ray florets and a similar number of disk florets. The petal-like rays are lavender or pale blue-violet, while the tiny corollas of the disk florets are bright yellow, later becoming orange-red. At the base of each flowerhead, there are 4-5 series of appressed floral bracts. Individual floral bracts are scale-like in appearance and linear-oblong in shape; each of these bracts is medium green along the upper one-half of its length, otherwise it is nearly white. The blooming period occurs from early to mid-fall and lasts about 1 month. Both disk and ray florets produce achenes.Stem & Leaves The small achenes are bullet-shaped and pubescent; there is a small tuft of hairs at the apex of each achene. For each tuft, the spreading inner hairs are long, while the outer hairs are short. The tufted achenes are distributed by the wind. The root system forms a caudex with fibrous roots; sometimes, spreading rhizomes are produced, from which vegetative offsets can develop. Cultivation: The preference is full or partial sun, dry-mesic conditions, and an acidic soil that is sandy or rocky. This wildflower can be cultivated in rock gardens. Range & Habitat: The native Flax-Leaved Aster is occasional in the northern half of Illinois, while in the southern half of the state it is rare or absent (see Distribution Map). Habitats include upland sand prairies, upland sandy savannas, stabilized sand dunes, open rocky woodlands, rocky wooded slopes, and sandstone glades. This wildflower is found in high quality natural habitats with sparse ground cover. It benefits from occasional wildfires in wooded areas, as this reduces the encroachment of woody vegetation. Faunal Associations: The nectar and pollen of the flowerheads attract many kinds of insects, including long-tongued bees, short-tongued bees, various flies, butterflies, skippers, and beetles. Several bees are pollinator specialists (oligoleges) of Aster spp. (Asters): Andrena asteris, Andrena asteroides, Andrena hirticincta, Andrena nubecula, Andrena simplex, Andrena solidaginis, and Colletes simulans armata. Some of these bees are also oligoleges of Solidago spp. (Goldenrods). Other insects feed on the leaves, flowers, seeds, plant juices, stalks, or roots of Asters. These species include the plant bug Plagiognathus cuneatus, the leafhopper Macrosteles quadrilineatus, Exema canadensis and other leaf beetles, the long-horned beetle Mecas pergrata, several aphids (mainly Uroleucon spp.), and caterpillars of the butterflies Chlosyne nycteis (Silvery Checkerspot) and Phyciodes tharos (Pearl Crescent). There are also many moth species whose caterpillars feed on Asters (see Moth Table). Among vertebrate animals, the Ruffed Grouse and Wild Turkey eat the leaves and seeds, while the Cottontail Rabbit and White-Tailed Deer browse on the foliage. The White-Footed Mouse and possibly other small rodents also eat the seeds.
Photographic Location: An upland sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois. Comments: This wildflower has an elegant appearance. What distinguishes Flax-Leaved Aster from species in the Aster genus are the tufted hairs of its achenes: they consist of a combination of long and short hairs, rather than hairs of uniform length. Nonetheless, it is sometimes referred to as Aster linariifolius because of its similarity to these species in other respects. Flax-Leaved Aster superficially resembles Aster oblongifolius (Aromatic Aster) to some extent, but it has unbranched stems, while the latter species has abundantly branched stems. Because of its short linear leaves, which are arranged in dense pseudo-whorls, Flax-Leaved Aster is relatively easy to identify. Another common name of this species is Stiff-Leaved Aster.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This is a perennial wildflower about 2½-6' tall that is either unbranched or sparingly branched. The central stem is light gray-green, densely pubescent, terete, and rather stout. Alternate leaves occur at intervals along this stem. Individual leaves are up to 7" long and 6" across; they are oval-cordate in outline with 3-7 palmate lobes and crenate-dentate margins. Usually the middle lobes of the leaves are larger than the lateral lobes. The upper surface of these leaves is medium green and hairless to sparsely pubescent, while their lower surface is light gray-green and pubescent. The petioles are up to 6" long, light gray-green, and pubescent. Sometimes short secondary stems with small leaves develop from the axils of the leaves on the central stem. Flowers are produced either individually or in clusters of 2-3 from the axils of the leaves along the upper half of each plant. The pedicels of these flowers are rather short (up to ¾" long), light gray-green, and pubescent. Each flower is 1¼-2½" across, consisting of 5 light pink petals (obcordate in shape), 5 light gray-green sepals (ovate in shape) that are joined together at the base, a central reproductive column, and 3 light gray-green floral bracts (linear in shape). Individual sepals are about ½" in length, while individual floral bracts are about the same length; both floral bracts and sepals are short-pubescent. The stamens are located along the outer half of the reproductive column, while the styles are located at its tip. The anthers of the stamens are pale yellow or white. The blooming period occurs during the summer, lasting about 2 months. Individual flowers are short-lived and slightly fragrant. Afterwards, each fertile flower is replaced by a ring of carpels containing the seeds. The carpels are reniform and narrowly wedge-shaped; their outer edges are pubescent. Each carpel contains 2-4 seeds (about 3 mm. in length). The root system consists of a short stout taproot and rhizomes. Vegetative colonies of plants occasionally develop from the rhizomes. Cultivation: The preference is full or partial sun, moist to mesic conditions that are well-drained, and soil containing some loam or rocky material. Germination of the seeds requires scarification of the seed coat through mechanical means or by fire. In a dormant state, the seeds can be remain viable for up to 50 years. Cross-pollination with genetically distinct plants is required for the production of viable seeds.
Range & Habitat: The native Kankakee Mallow has been found only in Kankakee County, where it is rare and state-listed as 'endangered' (see Distribution Map). Habitats consist of rocky riverbanks, woodland edges, open rocky woodlands, and abandoned fields. In all of these habitats within Illinois, the underlying bedrock of the thin soil consists of dolomite. Occasional wildfires are beneficial in maintaining populations of Kankakee Mallow as they stimulate the germination of seeds and reduce competition from woody vegetation. This wildflower has been cultivated successfully in gardens. Faunal Associations: Very little is known about floral-faunal relationships for this rare wildflower. The flowers are probably cross-pollinated by various long-tongued and short-tongued bees. White-Tailed Deer and other mammalian herbivores readily browse on the foliage. It may be necessary to place wire cages over individual plants in order to protect them from such animals.
Photographic Location: A flower garden in Urbana, Illinois. Comments: The Kankakee Mallow has attractive flowers and foliage. This rare wildflower is endemic to Illinois, although an adventive population has been found in Indiana near a railroad. It is thought that members of a Chicago wildflower society may have established this population by throwing seeds of the Kankakee Mallow out of the window of a passing train during the early 20th century. There are some differences of opinion regarding the taxonomic classification of the Kankakee Mallow. It has been classified as the typical variety of a more western species, Iliamna rivularis (Mountain Hollyhock), and sometimes it is considered the same species as the more eastern Iliamna corei (Peter's Mountain Mallow). This last species was discovered on a sandstone outcrop in Virginia, where it was under attack by feral goats. The Kankakee Mallow differs from Peter's Mountain Mallow by having flowers that are fragrant. In general, mallows of the Iliamna genus differ from many other mallows by having 3 linear floral bracts behind the sepals of each flower.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
Description: This perennial vine is up to 30' long; it dies back to the ground each year. The stems are light green or light tan, stout, and smooth to prickly-bristly. The opposite leaves are up to 6" long and 4" across; smaller leaves are usually oval-cordate in shape, but larger leaves are palmate with 3 lobes (rarely with 5). These leaves have a rough texture and coarse serration along the margins; they are medium green or yellowish green on their upper surfaces, and whitish green below. The long petioles are light green or light tan, stout, and prickly-bristly. At the base of each petiole is a pair of lanceolate stipules. The hairiness or pubescence of the stems and leaves is variable, if it is present at all. Usually, there are small white hairs along the major veins on the leaf undersides; sometimes these veins are also prickly. American Hops is dioecious, with male (staminate) and female (pistillate) plants. The male plants produce drooping panicles of staminate flowers. These panicles are up to 12" long and 6" across; they contain numerous small flowers that are yellowish or whitish green. Each staminate flower has 5 sepals, 5 stamens, and no petals. It has a star-like appearance and spans about ¼" across, hanging downward from a slender pedicel that is often slightly pubescent. The non-sticky pollen is produced in great abundance and it is easily dispersed into the air. The female plants produce odd-looking cone-shaped spikes of pistillate flowers (aments) from the axils of the leaves. A spike of pistillate flowers is up to 3" long, 2" across, and ovoid in shape; it usually hangs downward from a slender peduncle. The pistillate spike consists of overlapping green bracts that are ovate; there is a pair of pistillate flowers tucked between each adjacent pair of bracts. Each pistillate flower consists of little more than an ovary with a sticky stigma that is long and slender. Both the male and female flowers bloom during the late summer for about 2 weeks. The male flowers quickly turn brown and wither away, while the fruits (or aments) of the female flowers persist longer and gradually turn brown. Each pistillate flower produces a capsule with a single seed that is resinous and aromatic. This vine reproduces by reseeding itself.
Cultivation: The preference is partial or full sun, fertile soil, and moist to slightly dry conditions. This robust vine will also grow in poor soil that is rocky or gravelly. It can be quite aggressive and appears to have few problems with disease. Range & Habitat: The native American Hops is a common plant that occurs in most areas of central and northern Illinois. However, it less common or absent from many areas of southern Illinois (see Distribution Map). Other varieties of this vine also occur in Eurasia. American Hops occurs in openings of both upland and floodplain forests, woodland borders, thickets, and slopes of bluffs. In more developed areas, it is found along fence rows, vacant lots, areas along railroads, and miscellaneous waste areas. This plant favors areas that are more or less disturbed, whether from human activities or natural causes. It often clambers over surrounding vegetation, including shrubs and small trees.
Faunal Associations: Pollination is by wind, rather than insects. However, the abundant pollen of the staminate flowers attracts flower flies (Syrphidae) and small bees. The caterpillars of several butterflies feed on hops (Humulus spp.), including Vanessa atalanta (Red Admiral), Polygonia interrogationis (Question Mark), Polygonia comma (Comma), and Strymon melinus (Gray Hairstreak). The caterpillars of the latter species feed on the fruits and developing seeds. The caterpillars of some moths also feed on hops; they include Eudryas grata (Beautiful Wood Nymph), Hydraecia immanis (Hop Vine Borer Moth), Hypena humuli (Hop Looper), and Cnephasia longana (Omnivorous Leaftier). Other insect feeders include Taedia hawleyi (Hop Plant Bug), Phorodon humuli (Hop Aphid), Psylliodes punctulata (Hop Flea Beetle), larvae of Lasioptera humulicaulis (Hop Stem Gall Midge), and the thrips Neohydatothrips beachae. Little information appears to be available about this vine's relationships to vertebrate animals, however it undoubtedly provides protective cover for many species of birds and mammals.
Photographic Location: A sunny area along an abandoned railroad in Urbana, Illinois. This vine also occurred in partially shaded areas at the same locality. Comments: American Hops has some resemblance to grapevines (Vitis spp.), but it is a coarser and more bristly vine that flowers late in the year, while the latter flowers during the spring. The female fruit of hops is used to flavor beer and prevent decay during fermentation from bacterial processes. It is possible that the wind-dispersed pollen may cause allergic reactions in some people. There are both European and American varieties of this species, and it is quite possible that they have interbred in the wild. Consequently, they are often hard to distinguish. There is a variety of American Hops that has unlobed leaves. There is an invasive non-native species of hops that occurs in the wild, Humulus japonicus (Japanese Hops). This is an annual vine that has leaves with more lobes (5-7) than American Hops. Furthermore, the lobes of its leaves are more narrow and pointed.
0
0
文章
Miss Chen
2018年03月27日
Miss Chen
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.
0
0
文章
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206
相关用户
筒叶花月
筒叶花月
来自： 斑目
玉露
玉露
来自： 安静的种花人
玉露
玉露
来自： 石头剪子布
天津
玉露
玉露
来自： 绿野鱼悅
温州市
筒叶花月
筒叶花月
来自： Heidi Liu
玉露
玉露
来自： 一万吨少女心
筒叶花月
筒叶花月
来自： KiddaHoo
郑州
保利安娜
保利安娜
来自： 辣木姐--璐颖
玉露
玉露
来自： 倾心
福州
玉露
玉露
来自： 小欢喜
广州
举报 反馈

您有什么意见或建议，欢迎给我们留言。

请输入内容
提交
取消
设置
VIP
退出登录
关闭
分享

分享好文，绿手指（GFinger）养花助手见证你的成长。

关闭
请前往电脑端操作

请前往电脑端操作

关闭
转发
插入话题
提醒好友
发布
/
提交成功 提交失败 最大图片质量 成功 警告 啊哦！ 出了点小问题 转发成功 举报 转发 显示更多 _zh 文章 求助 动态 刚刚 回复 邀你一起尬聊！ 表情 添加图片 评论 仅支持 .JPG .JPEG .PNG .GIF 图片尺寸不得小于300*300px 最少上传一张图片 请输入内容