动态第350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09日

Prairie Rose Rosa arkansana suffulta Rose family (Rosaceae) Description: This small shrub is ½-2' tall, branching occasionally. The terete stems are woody and brown below, becoming non-woody and light green above; they are densely covered with fine straight prickles. Alternate compound leaves develop along the non-woody stems; they are 4-5" long, 2½-3" across, and odd-pinnate with 7-11 leaflets. Each compound leaf has a pair of stipules at its base about ¾-1" long; the stipules are light green and smooth along their margins, tapering to a pair of pointed tips. The petioles of the compound leaves are light green to red between their stipules. Individual leaflets are 1-1½" long and about one-half as much across; they are broadly oblong to oblong-obovate in shape and their margins are coarsely serrated. The tips of the leaflets are blunt, while their bottoms are wedge-shaped (cuneate) to rounded. The upper surface of the leaflets is medium to dark green and glabrous, while the lower surface is light green and covered with fine short pubescence. The leaflets are either sessile or they have short petioles less than 1/8" in length. The rachises (central stalks) of the compound leaves are light green to reddish green and they are covered with short fine pubescence. The rachises are also grooved above and rounded below; fine straight prickles along their undersides may, or may not, be present. Close-up of Flower Flowers are produced from upper stems either individually or in groups of 2-4 on short corymbs (usually the latter). The flowering stalks are light green and glabrous. Each flower is 1½-2" across, consisting of 5 pink petals (rarely white), 5 green sepals, a ring of numerous stamens, a flattened cluster of short styles, and an inferior ovary that is glabrous. The petals are obovate-orbicular in shape; sometimes they are somewhat bicolored with rays of pink on a lighter background. The sepals are narrowly lanceolate and about one-half the length of the petals. The stamens and styles are more or less yellow. The blooming period occurs from late spring to mid-summer, lasting about 3 weeks. Individual flowers last only a few days and they are fragrant. Afterwards, the flowers are replaced by rose hips that are up to ½" across, globoid in shape, glabrous, and bright red at maturity during the late summer or fall. The fleshy interior of each rose hip is rather dry and contains several seeds. At the tip of each rose hip, there persists 5 dried sepals; these sepals are widely spreading. The chunky seeds are about 4 mm. in length. The root system is woody, branching, and rather deep. Sometimes small clonal colonies of plants are produced from underground runners. Cultivation: The preference is full or partial sun, mesic to dry conditions, and a somewhat barren soil that contains clay, rocky material, or sand. The hard seeds are difficult to germinate and can lie dormant in the ground for many years. However, once individual plants become established, they are easy to manage. Drought-resistance is excellent. [图片]Range & Habitat: The native Prairie Rose occurs occasionally in northern Illinois and scattered counties elsewhere within the state (see Distribution Map). Illinois lies near the western range limit of this species in North America. Habitats include upland prairies, hill prairies, limestone glades, roadside embankments, areas along railroads, pastures, abandoned fields, and fence rows. This small shrub tends to increase in response to light or moderate grazing from cattle and other mammalian herbivores. This shrub is also well-adapted to occasional wildfires, as it is able to regenerate from its deep root system. Faunal Associations: The flowers offer only pollen as a reward to visiting insects. These floral visitors include bumblebees and other long-tongued bees, Halictid bees, Andrenine bees, various beetles, and Syrphid flies. The Syrphid flies are too small to effectively cross-pollinate the flowers. An oligolectic bee, Synhalonia rosae, is a specialist pollinator of Rosa spp. (roses). Many kinds of insects also feed on the foliage, stems, and other parts of roses. These insect feeders include grasshoppers, thrips, plant bugs, aphids, leafhoppers, larvae of gall flies, larvae of gall wasps, weevils, flea beetles, larvae of wood-boring beetles, larvae of sawflies, and caterpillars of moths. Some examples of these insects include Heterothrips analis (Wild Rose Thrips), Dasineura rhodophaga (Rose Midge), Rhagoletis basiolum (Rose Hip Maggot), Typhlocyba rosae (Rose Leafhopper), Acyrthosiphon dirhoda (Rose-Grass Aphid), Merhynchites bicolor (Rose Curculio), Altica rosae (Rose Flea Beetle), Macrodactylus subspinosa (Rose Chafer), Allantus cinctus (Curled Rose Sawfly), and Parasa indetermina (Stinging Rose Caterpillar). Among vertebrate animals, the Greater Prairie Chicken and Bobwhite Quail feed on the rose hips, while the Cottontail Rabbit and White-Tailed Deer feed on the foliage (and sometimes the rose hips). When the rose hips are eaten by these animals, the seeds of Prairie Rose are carried to new locations where they can germinate. This is because the hard coats of the seeds enable them to survive passage through the gastrointestinal tract of such animals. [图片]Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois. Comments: Prairie Rose is one of several rose species (Rosa spp.) in Illinois. This dwarf shrub has surprisingly large and showy flowers that can occur in various shades of pink, depending on the local ecotype. Prairie Rose is similar in appearance and size to the native Pasture Rose (Rosa carolina), but it differs from the latter species in the following ways: 1) its flowering stalks and ovaries are hairless, rather than glandular-hairy, 2) the sepals of its rose hips are usually more persistent, 3) its stems are more densely covered with straight fine prickles, 4) its flowers are more often produced in groups of 2-4, rather than individually, 5) its compound leaves tend to have more leaflets (usually 9). There are two varieties of the Prairie Rose, of which only Rosa arkansana suffulta is native to Illinois. The typical variety, Rosa arkansana arkansana, differs by having leaflet undersides that are hairless. This latter variety occurs rarely within the state as an adventive plant from the west. Unlike most authorities, Mohlenbrock (2002) prefers to classify Rosa arkansana suffulta as a distinct species, Rosa suffulta. Another common of this shrub is the Sunshine Rose.

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Miss Chen

2018年02月09日

Description: This herbaceous perennial plant is up to 4' tall while in flower. The long slender stems are slightly ridged. The basal leaves occur toward the bottom of these stems and are irregularly shaped – the larger leaves are pinnately divided into 3-7 lobes, sometimes subdividing further into 1-2 secondary lobes. The margins of these leaves are smooth, or sparsely dentate; they are individually up to 8" long and 5" across. The smaller leaves higher up on the stems are usually lanceolate; they are few in number. The texture of these leaves is rough as a result of tiny stiff hairs and bumps. The daisy-like composite flowers occur at the apex of the tall stems. Each composite flower has up to 13 drooping yellow ray florets spanning 1-2½" across, and an oblong head of disk florets that is about ½–¾" tall when mature. This head is initially light green or grey, but later becomes dark brown. The blooming period occurs from early to late summer, and lasts about 1-2 months. There is little or no floral scent – although the seedheads release an anise scent when they are crushed. The root system is rhizomatous, often forming tight clumps of plants. The dark achenes are without tufts of hair. [图片]Cultivation: The preference is full sun, mesic conditions, and a loam or clay-loam soil. However, this is a robust plant that will tolerate partial sun, moist to slightly dry conditions, and many kinds of soil. Foliar disease doesn't affect the leaves until after the blooming period. There is a tendency for the flowering stems to flop around if this plant is spoiled by too much water or fertile soil. This plant is easy to grow. Range & Habitat: The native Yellow Coneflower is fairly common in Illinois, except in some SE counties (see Distribution Map). Habitats include moist to slightly dry black soil prairies, clay prairies, thickets, woodland borders, limestone glades, and areas along railroads, particularly where remnant prairies occur. Yellow Coneflower tends to colonize the more disturbed areas of these habitats. Close-up of Compound Leaf Faunal Associations: Many kinds of insects visit the flowers, but especially bees, including Epeoline Cuckoo bees, large Leaf-Cutting bees, Green Metallic bees, and other Halictine bees. Other insect visitors include wasps, flies, small butterflies, and beetles. These insects suck nectar from the flowers, although the bees also collect pollen and some beetles feed on pollen. The caterpillars of the butterfly Chlosyne nycteis (Silvery Checkerspot) feed on Yellow Coneflower, as well as the caterpillars of the moths Eynchlora acida (Wavy-Lined Emerald) and Eupithecia miserulata (Common Eupithecia). Goldfinches occasionally eat the seeds, while some mammalian herbivores eat the foliage and flowering stems, particularly groundhogs and livestock. [图片]Photographic Location: Photographs were taken at a prairie of Parkland College in Champaign, Illinois. Comments: Yellow Coneflower is an excellent choice for a wildflower garden because of its long blooming period and attractive yellow flowers. The entire plant is delicately constructed, and has a tendency to sway or flutter with each passing breeze. This species can be distinguished from other yellow coneflowers, such as Rudbeckia hirta, by its drooping ray florets and the complex structure of the basal leaves.

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Miss Chen

2018年02月09日

Description: This perennial wildflower is 1-3' tall, branching occasionally. The stems are medium green and minutely rough-pubescent to glabrous. The spreading alternate leaves are up to 6" long and 2" across; they are pinnatifid or double-pinnatifid with 5-11 lobes, medium green, and minutely rough-pubescent to glabrous. The slender lobes are linear-oblong and sometimes have 1-2 dentate teeth or smaller cleft lobes; they are 1/3" (8 mm.) across or less. Irregularities in the structure of the leaves are rather common. The petioles are up to 2" long. Occasionally, the upper stems terminate in individual flowerheads on long naked stalks (peduncles). These stalks are 2-12" long and finely grooved. The flowerheads are about 1½–3" long and a little less across. Each flowerhead consists of a cylindrical head of numerous disk florets, which is surrounded by 4-11 drooping rays (ray florets). A mature head of disk florets is ¾–1¾" long; it is initially gray or greenish gray, later becoming dark brown. The rays are about ½–1¼" long, oblong in shape, and slightly notched at their tips; they are either yellow, maroon (reddish brown), or yellow with basal patches of maroon. The typical form of Mexican Hat has yellow rays, while plants with maroon rays are referred to as f.Distribution Map pulcherrima. The bottom of each flowerhead is defined by 2 series of small narrow bracts; these are largely hidden by the drooping rays. The blooming period occurs during the summer and lasts about 1-2 months. Fertile disk florets are replaced by small oblongoid achenes; each achene usually has one or more tiny scales at its apex. This plant spreads to new areas by reseeding itself. Cultivation: The preference is full sun, dry conditions, and a relatively barren soil containing clay, gravel, or sand. On moist fertile ground, this wildflower has trouble competing with taller and more aggressive plants. Range & Habitat: Mexican Hat is adventive from the the Great Plains and western states; the eastern boundary of its range extends into western Iowa and Missouri. In Illinois, naturalized populations of Mexican Hat are uncommon; they are found primarily in the northern and western sections of the state. Habitats include upland prairies, roadsides, areas along railroads, and barren waste areas. This wildflower is often cultivated in gardens, from which it sometimes escapes. In Illinois, Mexican Hat is found primarily in disturbed areas, where it may or may not persist. Faunal Associations: Various insects are attracted to the nectar and pollen of the flowerheads. Floral visitors of Mexican Hat are probably similar to those insects that are known to visit the flowerheads of Ratibida pinnata (Yellow Coneflower). Likely visitors include various short-tongued bees, wasps, flies, beetles, and the occasional butterfly or skipper. The caterpillars of some moths are known to feed on Ratibida spp. (primarily the rays and florets). These species include Homoeosoma electellum (Sunflower Moth), Chlorochlamys chloroleuca (Blackberry Looper Moth), Eupithecia miserulata (Common Pug), Synchlora aerata (Wavy-Lined Emerald), and Epiblema iowana (Tortricid Moth sp.). The caterpillars of the latter moth feed on the roots. Photographic Location: A flower garden in downtown Champaign, Illinois. The photographed plant is Ratibida columnifera pulcherrima. [图片]Comments: This is a colorful prairie wildflower. Mexican Hat can be distinguished from Ratibida pinnata (Yellow Coneflower) by its long cylindrical heads, which usually exceed the length of the rays at maturity. The ovoid-globoid heads of Yellow Coneflower, in contrast, are much shorter than the length of their rays. Other common names of Ratibida columnifera are Long-Headed Coneflower and Prairie Coneflower. The common name that is used here, 'Mexican Hat,' refers to the fancied resemblance of the flowerhead to a sombrero.

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Miss Chen

2018年02月09日

Description: This is a perennial herbaceous plant up to 3' tall and branching frequently, often with a bushy appearance. The green or reddish stems are strongly four-angled and have scattered white hairs along the ridges. The opposite leaves are up to 2½" long and narrowly lanceolate or linear. They are sessile, and have smooth margins. The largest leaves are ¼ - ½" across. When damaged, the foliage releases a strong mint scent. Numerous flattened heads of small white flowers (often with purple dots) occur at the ends of the upper stems. Each head is up to ¾" across and can contain up to 50 flowers. However, only a few of these are in bloom at the same time, beginning with the outer circle of flowers and ending towards the center. Each tubular flower is about 1/8" long and 2-lipped. The blooming period occurs during the middle of summer and lasts about a month. Each small flower produces 4 tiny, finely pitted, dull black seeds. These seeds are distributed to some extent by the wind. The root system produces rhizomes, which spread a short distance from the mother plant. Soon, a small colony of plants are formed vegetatively. Cultivation: The preference is full or partial sun, and moist to average conditions. The soil can contain loam, sand, clay, or gravel – this plant is not fussy about soil texture. During drought, the lower leaves will turn yellow and fall off. This plant is easy to grow, and less subject to foliar disease than some other mints, such as Monarda spp. However, stressed out plants sometimes succumb to rust. Range & Habitat: The native Common Mountain Mint is widely distributed in Illinois, but it is uncommon or absent from southern Illinois and a few western counties (see Distribution Map). This plant is occasional to locally common in moist to mesic black soil prairies. Other habitats include moist sand prairies, moist meadows in woodland areas, thickets, fens, swamps, and rocky bluffs. This is probably the most common Mountain Mint in Illinois. [图片]Faunal Associations: Many insects are strongly attracted to the flowers, including various bees, wasps, flies, small butterflies, and beetles. Typical visitors from these groups include honeybees, Cuckoo bees, Halictid bees, Sphecid wasps, Eumenine wasps, bee flies, Tachinid flies, Wedge-shaped beetles, and Pearl Cresecent butterflies. Most of these insects seek nectar. Mammalian herbivores and many leaf-chewing insects apparently find the mint fragrance of the leaves and stems repugnant, and rarely bother this plant. Photographic Location: The photographs were taken at a prairie of Parkland College in Champaign, Illinois. Comments: The name 'Mountain Mint' is something of a misnomer, because this plant and other similar species in this genus do not usually occur in mountainous habitats. Common Mountain Mint is similar in appearance to Pycnanthemum tenuifolium (Slender Mountain Mint). It can be distinguished from the latter species by the white hairs along the ridges of its stems, and the occurrence of leaves greater than ¼" across. The stems of Slender Mounntain Mint lack hairs.

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Miss Chen

2018年02月09日

Description: This perennial herbaceous plant is 1-3' tall, branching frequently to create a bushy effect. The slender stems are hairless. The slender opposite leaves are up to 3" long and ¼" across. Each leaf is sessile, linear, and hairless, with a prominent central vein and smooth margins. [图片]The upper stems terminate in small flat heads of flowers. The short tubular flowers are white, often with scattered purple dots, and individually about ¼" long. The corolla is divided into an upper lip and a lower lip with three lobes. The reproductive structures of each flower are white, except that the anthers are purple. The calyx is divided into several slender green lobes. The blooming period is early to mid-summer, and lasts about 1–1½ months. There is no floral scent, although the foliage has a mild mint scent and somewhat stronger minty taste. The small dark seeds are without tufts of hairs, but are small enough to be dispersed by gusts of wind. The root system consists of a taproot and rhizomes. Slender Mountain Mint can spread vegetatively, forming colonies of closely bunched plants. Cultivation: The preference is full sun and moist to slightly dry conditions. This plant often grows in rich loam, as well as soil containing rocky or gravelly material. Foliar disease is less troublesome for this mint species than many others. The leaves may assume a yellowish appearance during a major drought. This is an easy plant to grow. [图片]Range & Habitat: The native Slender Mountain Mint occurs occasionally in every county of southern and central Illinois, but is less common and more sporadic in northern Illinois (see Distribution Map). Habitats include moist to slightly dry black soil prairies, moist meadows and gravelly areas along rivers, openings in woodlands, moist thickets, acid gravel seeps, limestone glades, and abandoned fields. Faunal Associations: The flowers are very attractive to many kinds of insects, including long-tongued bees, short-tongued bees, wasps, flies, butterflies, skippers, beetles, and plant bugs. These insects usually seek nectar. Among the wasps, are such visitors as Thread-Waisted wasps, Bee Wolves (Philanthus spp.), Scoliid wasps, Tiphiid wasps, Sand wasps, Spider wasps, and Eumenine wasps. Flies visitors include Soldier flies, Syrphid flies, Mydas flies, bee flies, Thick-Headed flies, and Tachinid flies. The seeds are too small to be of much interest to birds. Mammalian herbivores usually don't browse on this plant because of the minty taste; the foliage may contain anti-bacterial substances that disrupt the digestive process of herbivores. Photographic Location: The photographs were taken at Meadowbrook Park in Urbana, Illinois. Comments: This plant has a delicate, somewhat airy appearance. Slender Mountain Mint closely resembles Pycnanthemum virginianum (Common Mountain Mint), except that the former has hairless stems and leaves that never exceed ¼" across. Common Mountain Mint, on the other hand, has lines of white hairs on its stems, and some of the larger leaves will exceed ¼" across. This latter plant tends to be taller, stouter, and less branched in appearance; it also blooms a little later in the year. The photographed flowering plant is still in the bud stage, while the photographed flowerheads are beginning to bloom.

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Miss Chen

2018年02月08日

Description: This herbaceous perennial plant is 2-4' tall, branching frequently to create a slender bushy appearance. The stems are light green, 4-angled, and densely pubescent on all sides. Pairs of opposite leaves occur along these stems, becoming gradually smaller and more slender as they ascend. These leaves are up to 1-3" long and ¼–¾" across; they are narrowly lanceolate to lanceolate in shape and either sessile or short-petiolate. The leaf margins are entire (toothless) and ciliate. When petioles are present, they are light green and densely short-pubescent. The upper leaf surface is grayish green and short-pubescent, while the lower leaf surface is slightly more pale and densely pubescent. The foliage has a typical mint fragrance. The upper stems terminate in branching flowerheads of flowers; individual heads are flat-topped and densely flowered, spanning up to 1" across. Flowerbud Heads Each flower is about ¼" long (from upper lip to lower lip), consisting of a 2-lipped corolla, a long-tubular calyx with 5 teeth, 4 stamens, and a pistil. The corolla is white; there are purple specks and dots scattered across its throat and the lobes of its lips. The upper lip of the corolla consists of a short hood, while its lower lip is longer and 3-lobed. The sides of the calyx tube are light green, vertically ribbed, and pubescent; the teeth along the upper rim of the calyx are erect and narrowly triangular in shape. At the base of each flowerhead, there occurs several leafy bracts that are up to 1" long; they are grayish green, lanceolate in shape, and pubescent. The margins of these bracts are entire and ciliate. The blooming period occurs from mid- to late summer, lasting about 1 month. Afterwards, the flowers are replaced by tiny seeds (4 seeds per flower); these seeds are hidden from view by the persistent calyces. Individual seeds are about 1 mm. long, oblongoid in shape, and dark brown. The root system is rhizomatous, often forming a dense tuft of clonal offsets. [图片]Cultivation: The preference is full or partial sun and moist to slightly dry conditions. Growth is best in fertile loamy soil, although other kinds of soil are acceptable, including those that are stony or clayish. During hot dry weather, some of the leaves may turn yellow and fall off, but the plant usually survives. Occasionally, some of the leaves may be affected by rust, especially when a plant is stressed out by adverse weather or is suffering from transplant shock. This problem is almost always temporary. Some protection from afternoon sun and occasional watering during dry spells can keep this plant healthy; fertilizer is neither necessary nor desirable. Overall, this is an easy plant to cultivate in gardens. Range & Habitat: The native Hairy Mountain Mint occurs occasionally in central Illinois, but it is uncommon or absent in the southern and northern sections of the state (see Distribution Map). Habitats include black soil prairies, meadows in wooded areas, rocky upland forests, woodland edges, savannas, thickets, limestone glades, and abandoned fields. Hairy Mountain Mint is usually found in higher quality natural areas, although it may colonize adjacent disturbed areas. Occasional wildfires or mowing may be beneficial in maintaining populations of this plant if it reduces competition from woody vegetation. [图片]Faunal Associations: The nectar-rich flowers are very attractive to many kinds of insects, including honeybees, cuckoo bees (Triepeolus spp., Coelioxys spp.), leaf-cutting bees (Megachile spp.), Halictid bees (Agapostemon spp., Halictus spp., Lasioglossum spp.), Halictid cuckoo bees (Sphecodes spp.), thread-waisted wasps (Ammophila spp.), the Great Golden Digger Wasp (Sphex ichneumoneus), the Black Grasshopper Wasp (Prionyx atratus), bee wolves (Philanthus spp.), paper wasps (Polistes spp.), Eumenine wasps (Euodynerus spp., Stenodynerus spp.), Syrphid flies, bee flies (Exoprosopa spp.), thick-headed flies (Conopidae), Tachinid flies, small- to medium-sized butterflies, and skippers (Robertson, 1929). Because of the frequent bee and wasp visitors to the flowers, parasitoid wedge-shaped beetles (Macrosiagon spp.) are often common on the flowers. These beetles lay their eggs on the flowers, and the hatched larvae attach themselves to their hosts and hitch-hike a ride back to the brood chamber, where they feed on the larvae and their food stores. Mountain mint (Pycnanthemum) is one of the host plants of a a stink bug, Neottiglossa cavifrons (Hart, 1919; Rider, 2009). Among vertebrate animals, Hairy Mountain Mint and other mountain mints have little value as sources of food. The seeds are too small to be of much interest to birds, while mammalian herbivores display little interest in the foliage, probably because of the chemicals that are associated with its strong mint fragrance. [图片]Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois. Comments: Some authorities refer to this plant as Pycnanthemum verticillatum var. pilosum. The appearance of Hairy Mountain Mint (Pycnanthemum pilosum) is similar to other mountain mints (Pycnanthemum spp.), but its leaves and stems are more hairy. Compared to two prairie species, Common Mountain Mint (Pycnanthemum virginianum) and Slender Mountain Mint (Pycnanthemum tenuiflorum), Hairy Mountain Mint has wider leaves. Other mountain mints that occur in Illinois are restricted to the southern section of the state, where they are found primarily in hilly woodlands. The fresh leaves of Hairy Mountain Mint can be boiled in water to make an excellent mint-flavored tea (personal observation).

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Miss Chen

2018年02月08日

Description: This herbaceous perennial wildflower is about 2-3' tall and abundantly branched above. The slender stems are light gray-green, terete, and canescent. Alternate compound leaves occur at intervals along these stems: they are either trifoliate (3 leaflets) or palmate (5 leaflets), spanning up to 3" long and across. The leaflets are up to 1½" long and 1/3" (8 mm.) across; they are gray-green, narrowly elliptic-oblong to oblong, and smooth along their margins. Raceme of Flowers The slender petioles are up to 1" long and usually shorter than the longer leaflets. At the base of each petiole, there is a pair of tiny linear stipules; these wither away with age. Occasionally, narrow racemes of blue-violet flowers are produced from the upper stems on long peduncles (up to 4" long). These racemes are 1½–3" long and loosely flowered; 1-4 flowers develop at intervals along each raceme. Individual pea-like flowers are up to ¼" long (6 mm.), consisting of 5 blue-violet petals and a short calyx with 5 teeth. The calyx of each flower is light green green to purple and more or less hairy. Each flower has a short slender petiole; at the base of each petiole, there is a tiny scale-like bract. The blooming period occurs from late spring to late summer and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a small seedpod about ¼" long that is ovoid and somewhat flattened, terminating abruptly into a short beak. Each seedpod contains only a single seed. The root system consists of a long slender taproot that runs deep into the ground. This wildflower reproduces by reseedingDistribution Map itself. Cultivation: The preference is full sun, dry conditions, and soil that contains gravelly material, a little sand, or clay-loam. New plants can be started from seeds, but growth and development are slow. Established plants don't produce foliage until rather late in the spring, but they develop quickly thereafter from the nutrients inside their taproots. Resistance to drought is excellent. Range & Habitat: The native Scurfy Pea is uncommon in Illinois, occurring from the NE section of the state to the west-central section in counties that are located near the Illinois river. Illinois lies along the eastern edge of its distribution. Habitats include hill prairies, dry upland prairies and gravel prairies, limestone glades, barren upland savannas, and areas along railroads. Scurfy Pea is usually found in high quality habitats, although it benefits from disturbance that reduces woody vegetation. In particular, it responds well to occasional wildfires. Faunal Associations: The flowers are pollinated primarily by small to medium-sized bees, including the Digger bee Svastra obliqua, the Plasterer bee Colletes willistoni, and the Dagger bee Calliopsis andreniformis. These bees are attracted to the nectar of the flowers. Some grasshoppers eat the foliage, including Melanoplus femurrubrum (Red-Legged Grasshopper), Melanoplus foedus (Striped Sand Grasshopper), and Melanoplus packardii (Packard's Grasshopper). The caterpillars of the flower moth Schinia jaguarina feed on the developing seedpods, while the leaf beetle Luperosoma parallelum feeds on the foliage. The foliage of Scurfy Pea is occasionally browsed by White-Tailed Deer and Cottontail Rabbits, even though it has been reported to be mildly toxic to livestock. It is possible that some upland gamebirds and granivorous songbirds eat the seeds, but records about this are lacking. Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois. [图片]Comments: This wildflower is more typical of prairies in regions that lie to the west of the Mississippi River. It has a rather loose bushy appearance with small blue-violet flowers. Two varieties of Scurfy Pea have been identified: the typical variety produces 1-2 flowers about 4-5 mm. long at intervals along each raceme, while var. floribunda produces 2-4 flowers about 6-7 mm. long at intervals along each raceme. Some specimens of Scurfy Pea may be intermediate in these characteristics and therefore difficult to classify according to variety. Scurfy Pea differs from similar species in the Bean family by having palmately compound leaves with 3-5 leaflets, a taller branching habit, petioles that are usually shorter than the leaflets, and rather loose racemes of small flowers. Another common name of this species is Wild Alfalfa; an older scientific name of this species is Psoralea tenuiflora.

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Miss Chen

2018年02月08日

Description: This plant is a summer annual or biennial that is erect and eventually becomes ¾–2½' tall. Some plants overwinter as a low rosette of leaves, while others complete their growth and development within a single year. After the rosette stage has passed, each plant has a central stem that is unbranched in the lower half, while short ascending branches develop in the upper half. The central and upper stems are whitish green to nearly white from the appressed woolly hairs that cover their surfaces. The alternate leaves are up to 3" long and 1/3" (8 mm.) across, becoming slowly smaller as they ascend the stems. The leaves are linear-oblong, smooth or minutely undulate along their margins, and sessile. The upper surface of each leaf is mostly hairless and dark green to yellowish green, while the lower surface is whitish green and covered with appressed woolly hairs. Each leaf has a prominent central vein. Compound Corymbs of Flowerheads Each upper stem terminates in a small corymb of 1-5 flowerheads; they are white to cream-colored. Each flowerhead is about ¼" long and about half as much across; it is conical-oblongoid in shape with a truncate apex. Later, each flowerhead becomes wider and more open as its achenes become mature. The sides of each flowerhead consist of many overlapping bracts that are white or cream-colored; these scale-like bracts are oblong-lanceolate to broadly oblong-lanceolate and they have blunt tips. At the apex of each flowerhead, there are many disk florets that are pale yellow to light brown; the innermost florets are perfect (both staminate and pistillate), while the remaining florets are pistillate. Each tiny floret is narrowly tubular. The blooming period occurs from late summer to early fall and lasts about a month. There is no noticeable floral scent, although the foliage often has a balsam-like fragrance. Each floret is replaced with a small bullet-shaped achene that has a tuft of white hairs at its apex. These hairs can separate from each other individually or in small groups; they are not united at the base. The root system is mostly fibrous. This plant spreads by reseeding itself. Cultivation: The preference is full sun, mesic to dry conditions, and a friable soil containing sand or silt. A little shade is tolerated. The seeds require light to germinate. Range & Habitat: The native Sweet Everlasting is occasional to locally common throughout Illinois (see Distribution Map). Habitats include upland prairies, sand prairies, typical savannas and sandy savannas, fallow fields, and areas along railroads and roadsides. Disturbed dry areas with scant vegetation are preferred. [图片]Faunal Associations: The nectar of the flowers attracts short-tongued bees (mainly Halictid), wasps, and flies primarily. Among the wasps, are such visitors as Eumenid wasps, Crabronid wasps, Paper wasps, Spider wasps, Cuckoo wasps, Weevil wasps, and many others (see Robertson, 1929). The Wild Turkey reportedly eats the foliage. White-Tailed Deer browse on the foliage during the winter. Photographic Location: At the edge of a field in Vermilion County, Illinois. Comments: This curious plant has woolly foliage and flowerheads that resemble those of Antennaria spp. (Pussytoes), Anaphalis margaritacea (Pearly Everlasting), Gamochaeta purpurea. (Early Cudweed), and some other members of the Aster family. Sweet Everlasting is more tall than Pussytoes and Early Cudweed, and its truncate-conical flowerheads are more narrow than the button-like flowerheads of Pearly Everlasting. There are other Pseudognaphalium spp. in the United States that are quite similar in appearance to Sweet Everlasting, but they have not been observed in Illinois. However, some of these species have been found in neighboring Indiana and other states further to the east. Sweet Everlasting's older scientific name is Gnaphalium obtusifolium (by which it is still commonly referred), but it has been reassigned to the genus Pseudognaphalium.

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Miss Chen

2018年02月08日

Description: This herbaceous perennial wildflower is 2-5' tall with an erect central stem that is unbranched. This stem is light green, terete, stout, and covered with short stiff hairs; it often becomes brown with age. The alternate leaves are up to 4½" and 2" across, becoming gradually smaller as they ascend the stem. They are lanceolate to broadly lanceolate, elliptic, orClose-up of Flowerhead oblanceolate in shape, medium green, and covered with short stiff hairs on their undersides. The margins of the lower leaves are dentate, while the margins of the upper leaves are more smooth. Most of the leaves are sessile, although some of the lower leaves may clasp the stem slightly; some of these leaves may wither before the blooming period. The foliage contains a bitter white latex. The central stem terminates in a spike-like raceme (or something similar to this) about ½–2' long. Along the central stalk of this raceme, are small clusters of flowerheads; small clusters of flowerheads also develop from the axils of the upper leaves. Each flowerhead is about ½–1" across, consisting of 10-18 ray florets and no disk florets. Each of these ray florets is white or cream-colored, linear-oblong in shape, and truncate at its tip with 5 small teeth. The base of each flowerhead is about ½" long and cylindrical in shape; it is covered with 8-10 phyllaries (floral bracts) that are light green, conspicuously hairy, and linear-oblong in shape. At the bottom of the flowerhead's base, there are several secondary phyllaries that are much smaller in size and insignificant. The reproductive organs of the ray florets consist of divided styles with strongly recurved tips and elongated stamens. The blooming period occurs from late summer to early fall and lasts about 2-3 weeks. Each fertile floret is replaced by an oblongoid achene with a small tuft of hairs. These hairs are straw-colored or light brown. Distribution of the achenes is provided by the wind. The root system consists of a stout taproot that is broadest toward the middle. This plant reproduces by reseeding itself. Cultivation: The preference is full sun and mesic to dry conditions. Different kinds of soil are tolerated, including those that are loamy, rocky, or sandy. It is difficult to establish this plant from seed as it is slow-growing and the young seedlings are vulnerable to "damping off" and other problems. Range & Habitat: Rough White Lettuce exists in widely scattered populations throughout Illinois (see Distribution Map), where it is native. Populations of this species have declined and it has become rather uncommon, largely because of the destruction of prairie habitat throughout the state. Habitats include black soil prairies, sand prairies, savannas, rocky upland woodlands, limestone glades, and prairie remnants along railroads. At one time, Rough White Lettuce was considered a weed in pastures, but this is no longer the case. Today, this conservative species is typically found in high quality prairies. Because of the difficulty in propagating this species, it is not often used in prairie restorations. Faunal Associations: There is a paucity of records about floral-faunal relationships for this species. Bumblebees visit the flowerheads for nectar. Cattle and other mammalian herbivores usually leave this plant alone because of its rough hairy foliage and bitter latex (see Ada Georgia, A Manual of Weeds, 1913). [图片]Photographic Location: The photograph of the flowerhead was taken by Pat Chapel (Copyright © 2006) at the Prospect Cemetery Prairie in Ford County, Illinois, while the photograph of the stem and leaves was taken by the webmaster at Loda Cemetery Prairie in Iroquois County of the same state. Comments: This is a true prairie plant that blooms during the fall. It is somewhat similar in appearance to Prenanthes racemosa (Glaucous White Lettuce), which prefers moist habitats. This latter species has a central stem that is glabrous and glaucous throughout, while the central stem of Rough White Lettuce has stiff short hairs. The color of the flowerheads is also somewhat different: the flowerheads of Glaucous White Lettuce often have a pale purple tint, while those of Rough White Lettuce are cream-colored or white. Other Prenanthes spp. in Illinois are normally found in woodlands, rather than prairies. In contrast to Rough White Lettuce, these woodland species have nodding flowerheads, widely spreading inflorescences, and leaves that are often deeply lobed.

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Miss Chen

2018年02月08日

Description: This perennial plant sprawls along the ground by means of stolons; it is less than 1' tall. The slender stems and stolons are initially green, but become red with age. Depending on the local ecotype, they can be nearly glabrous, or covered with spreading white hairs. The stolons can extend up to 3' and their tips often root in the ground, forming new plantlets. The compound leaves are palmate (with 5 leaflets) and alternate along the stolons or stems. Each leaflet is up to 3" long and ¾" across. There is coarse serration along the margins, except near the base, and prominent venation. The upper surface is glabrous, while the lower surface may be hairy or nearly glabrous. The leaflets are narrowly ovate (but with blunt tips), obovate, or oblanceolate; young leaflets often have their margins curled upward. A single yellow flower develops from a long pedicel from the upper axils of some of the compound leaves. This flower is about ½" across, and has 5 yellow petals that are narrow at the base, but rounded toward their tips, which are sometimes notched. The green calyx has 5 triangular tips that are a little shorter than the petals. The center of the flower has a somewhat flattened reproductive structure, which is surrounded by about 20 stamens. The blooming period can occur from spring to mid-summer, and lasts about a month. Only a few flowers are in bloom at the same time. There is no noticeable floral scent. The achenes are without tufts of hair. There is a short, thick rootstock that divides into coarse secondary roots. This plant often forms loose colonies by means of its stolons. [图片]Cultivation: The preference is partial to full sun, and moist to dry conditions. The soil can consist of loam, clay-loam, or contain gravelly material. This is an easy plant to grow that presents few problems. Range & Habitat: The native Common Cinquefoil occurs in every county of Illinois and it is fairly common (see Distribution Map). Habitats include mesic to dry black soil prairies, open upland forests, savannas, gravelly seeps, and abandoned fields. This plant occurs in both disturbed areas and high quality habitats. In tallgrass prairies, it is one of the understory plants. Faunal Associations: The flowers primarily attract small bees and flies, including Mason bees, Small Carpenter bees, Nomadine Cuckoo bees, Halictid bees, Syrphid flies, Tachinid flies, Blow flies, and others. Less common visitors are wasps, skippers, and butterflies. These insects seek nectar, although bees also collect pollen. The seeds are little used by birds. Small mammalian herbivores, such as rabbits and groundhogs, often eat the foliage. It is possible that some of the seeds of Common Cinquefoil can pass through their digestive tracts unharmed, and are thus distributed by them; some studies involving livestock have found this to be the case with a similar species, Potentilla recta (Sulfur Cinquefoil). Photographic Location: The above photographs were taken at Loda Cemetery Prairie in Iroquois County, Illinois. Comments: This is another plant that fits the stereotype of a weed, but it also occurs in prairies and other native habitats. The flowers are reasonably showy during the spring, but few in number. Common Cinquefoil resembles many other species of Cinquefoil, both native and introduced. Its compound leaves almost always have 5 leaflets, the flowers are bright yellow, and it sprawls along the ground; other species often have a fewer or greater number of leaflets, their flowers may be white or pale yellow, or they are erect. Common Cinquefoil is perhaps most similar to the native Potentilla canadensis (Dwarf Cinquefoil), except that the latter is a smaller plant with blunter leaftlets that are strongly obovate or oblanceolate.

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