文章
Miss Chen
2018年02月25日
Description: This biennial plant consists of a low-growing rosette of basal leaves up to 7" across during the 1st year. These basal leaves are up to 3½" long and ¾" across; they are green to greyish green, oblanceolate, dentate, and often slightly pinnatifid with shallow lobes. Their upper surface is often hairy, although they tend to become less hairy with age. During the 2nd year, Tower Mustard bolts during the spring and produces one or more flowering stalks up to 3½' tall. These stalks are light green to dull white, unbranched, hairless, and glaucous. Sometimes there may be a few hairs near the base of the stalks. The alternate cauline leaves are up to 3" long and 1" across. They are greyish green, lanceolate, smooth along the margins, hairless, and glaucous. Some of the lower cauline leaves may be dentate and slightly pinnatifid. The base of each cauline leaf clasps the stalk with a pair of basal lobes, which may be rounded or pointed. During cool spring weather, the cauline leaves may turn purple when they are exposed to full sun. Each stalk terminates in an elongated raceme of flowers and upright siliques (slender cylindrical seedpods). This raceme can become as long as the rest of the plant (up to 1¾' in length) and it has a tower-like appearance. Each flower at the apex of the raceme is up to 1/6" (4 mm.) across, consisting of 4 white or cream petals, 4 light green or yellow sepals, a stout style, and several stamens. The pedicels of the flowers and siliques are about ¼–½" in length.
The blooming period occurs during late spring to mid-summer and lasts about 1½ months. Each flower is replaced by a slender cylindrical silique up to 2½" long. The siliques are held upright close to stalk of the raceme. Each silique contains 1 or 2 rows of slightly flattened ovoid seeds. These small seeds have narrowly winged margins and they are dispersed to some extent by the wind. The root system consists of a stout taproot. This plant spreads by reseeding itself.
Cultivation: The preference is full sun to light shade, mesic to dry conditions, and loam, clay-loam, or rocky soil. This plant also tolerates soil containing sand or hardpan clay. It is fairly easy to grow from seed.
Range & Habitat: The native Tower Mustard occurs occasionally in the northern half of Illinois, but it is uncommon in the southern half of the state (see Distribution Map). Habitats include various kinds of prairies (sand, gravel, black soil, or clay), rocky open woodlands, barren savannas, limestone glades, rocky bluffs, and abandoned fields. In Illinois, Tower Mustard has low fidelity to any particular habitat. It also occurs in Eurasia.
Faunal Associations: Mostly small bees and flower flies visit the flowers for nectar or pollen. Occasionally various species of White butterflies (Pieridae) visit the flowers for nectar. The caterpillars of two Pierid butterflies, Anthocharis midea (Falcate Orangetip) and Euchloe olympia (Olympia Marble), prefer Arabis spp. (Rock Cresses) as a food source, particularly those Rock Cresses that are typically found in sunny habitats. The caterpillars of another Pierid butterfly, Pieris napi (Mustard White), reportedly feed on Rock Cresses, although this butterfly species hasn't been observed in Illinois since the 19th century. Little information appears to be available about the desirability of Tower Mustard as a food source for mammalian herbivores. However, the foliage is not particularly bitter nor peppery.
Photographic Location: The webmaster's wildflower garden in Urbana, Illinois.
Comments: Among the various Rock Cresses (Arabis spp. and related genera), Tower Mustard is mostly likely to be found in black soil prairies, although it also occurs in other kinds of habitats. The tower-like inflorescence gives this plant an odd appearance that is rather striking, especially when it becomes 3-4' tall. Because Tower Mustard is not difficult to grow and seems rather robust, it is rather surprising that this species is not more common. There are several Rock Cresses in Illinois, which can be found in either sunny or shady habitats, depending on the species. Some species have erect siliques that are appressed against the stalk of the raceme, while other species have siliques that are spreading or drooping. Tower Mustard belongs to the first group. Its appearance is similar to a very rare species, Arabis drummondii (Drummond's Rock Cress). This latter species has flattened siliques containing 2 rows of seeds and the style of its flowers is more slender than the style of Tower Mustard. Another species, Arabis hirsuta (Hairy Rock Cress), has hairs along at least the lower half of its flowering stalks, and it has flattened siliques containing a single row of seeds. The siliques of Tower Mustard are terete (round in cross-section). A scientific synonym of this plant is Arabis glabra.
The blooming period occurs during late spring to mid-summer and lasts about 1½ months. Each flower is replaced by a slender cylindrical silique up to 2½" long. The siliques are held upright close to stalk of the raceme. Each silique contains 1 or 2 rows of slightly flattened ovoid seeds. These small seeds have narrowly winged margins and they are dispersed to some extent by the wind. The root system consists of a stout taproot. This plant spreads by reseeding itself.
Cultivation: The preference is full sun to light shade, mesic to dry conditions, and loam, clay-loam, or rocky soil. This plant also tolerates soil containing sand or hardpan clay. It is fairly easy to grow from seed.
Range & Habitat: The native Tower Mustard occurs occasionally in the northern half of Illinois, but it is uncommon in the southern half of the state (see Distribution Map). Habitats include various kinds of prairies (sand, gravel, black soil, or clay), rocky open woodlands, barren savannas, limestone glades, rocky bluffs, and abandoned fields. In Illinois, Tower Mustard has low fidelity to any particular habitat. It also occurs in Eurasia.
Faunal Associations: Mostly small bees and flower flies visit the flowers for nectar or pollen. Occasionally various species of White butterflies (Pieridae) visit the flowers for nectar. The caterpillars of two Pierid butterflies, Anthocharis midea (Falcate Orangetip) and Euchloe olympia (Olympia Marble), prefer Arabis spp. (Rock Cresses) as a food source, particularly those Rock Cresses that are typically found in sunny habitats. The caterpillars of another Pierid butterfly, Pieris napi (Mustard White), reportedly feed on Rock Cresses, although this butterfly species hasn't been observed in Illinois since the 19th century. Little information appears to be available about the desirability of Tower Mustard as a food source for mammalian herbivores. However, the foliage is not particularly bitter nor peppery.
Photographic Location: The webmaster's wildflower garden in Urbana, Illinois.
Comments: Among the various Rock Cresses (Arabis spp. and related genera), Tower Mustard is mostly likely to be found in black soil prairies, although it also occurs in other kinds of habitats. The tower-like inflorescence gives this plant an odd appearance that is rather striking, especially when it becomes 3-4' tall. Because Tower Mustard is not difficult to grow and seems rather robust, it is rather surprising that this species is not more common. There are several Rock Cresses in Illinois, which can be found in either sunny or shady habitats, depending on the species. Some species have erect siliques that are appressed against the stalk of the raceme, while other species have siliques that are spreading or drooping. Tower Mustard belongs to the first group. Its appearance is similar to a very rare species, Arabis drummondii (Drummond's Rock Cress). This latter species has flattened siliques containing 2 rows of seeds and the style of its flowers is more slender than the style of Tower Mustard. Another species, Arabis hirsuta (Hairy Rock Cress), has hairs along at least the lower half of its flowering stalks, and it has flattened siliques containing a single row of seeds. The siliques of Tower Mustard are terete (round in cross-section). A scientific synonym of this plant is Arabis glabra.
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文章
Miss Chen
2018年02月25日
Description: This annual plant is unbranched. It is usually 4-12" tall, and rarely becomes taller. The central stem is light green and deeply grooved, with lines of small white hairs along the ridges. The alternate leaves are also light green, and strongly clasp the stem. However, at the top of the stem are a pair of opposite leaves. These leaves are up to 1" long and nearly as wide. They are broadly cordate, with wavy or dentate margins that are slightly ciliate. Along the margins, the leaves may assume a purplish color in bright sunlight. There is a milky sap in both the stem and leaves. From each leaf axil in the upper half of the plant, are 1-3 flowers, although only one of these will be in bloom at the same time. Each flower is deep violet or purple and about ½" across. It has a short tubular corolla with 5 spreading lobes. There are darker lines of purple that converge toward the throat of the flower. The throat is whiter than the rest of the flower, from which emerges a prominent white pistil and several stamens.
The blooming period occurs during the early summer and lasts about a month. There is no floral fragrance. This plant also produces self-pollinating flowers on the lower half of the stem, whose petals never open. The ovaries develop into small oval capsules, which split open into 3 parts to about the middle. This releases the numerous tiny seeds, which are lens-shaped and reddish brown. They are dispersed readily by the wind, and can be carried a considerable distance. The root system consists of a taproot.
Cultivation: The preference is full sunlight, and mesic to slightly dry soil. This plant flourishes best in poor soil that is either gravelly or sandy. It doesn't tolerate much competition from taller plants. Foliar disease is not a significant problem during the period of active growth and blooming, after which this plant will fade away.
Range & Habitat: The native Venus' Looking Glass is fairly common in the southern half of Illinois, but uncommon or absent in many areas of the northern half (see Distribution Map). Habitats include mesic to slightly dry sand prairies, gravel prairies, upland areas of black soil prairies, sandy savannas, lake borders, abandoned fields, and areas along railroads and roadsides, especially where it is gravelly or sandy. The habitats where this plant occurs have sparser and lower vegetation than many other areas as a result of poor soil or disturbance.
Faunal Associations: Small bees are the most common visitors of the flowers. This includes Little Carpenter bees, Plasterer bees, Green Metallic bees, and other Halictine bees. The Plasterer bee Colletes brevicornis is an oligolege of Venus' Looking Glass. Other insect visitors include bumblebees, flies, small butterflies, and skippers. The seeds are too small to be of any interest to birds. Mammalian herbivores may consume this plant, although it is of minor importance as a food source.
Photographic Location: The photographs were taken in a waste area along a gravel road near Champaign, Illinois.
Comments: When it is sunny, the flowers open up during the morning, and remain open for the rest of the day. They are attractive, but rather small. The common name of this plant probably refers to the shiny seeds of a related European species. The seeds of Venus' Looking Glass are too tiny to appear shiny to the unaided human eye. In form and color, the flowers of this plant resemble the flowers of Campanula americana (Tall Bellflower), but the former are much smaller. An older scientific name for this plant is Specularia perfoliata.
The blooming period occurs during the early summer and lasts about a month. There is no floral fragrance. This plant also produces self-pollinating flowers on the lower half of the stem, whose petals never open. The ovaries develop into small oval capsules, which split open into 3 parts to about the middle. This releases the numerous tiny seeds, which are lens-shaped and reddish brown. They are dispersed readily by the wind, and can be carried a considerable distance. The root system consists of a taproot.
Cultivation: The preference is full sunlight, and mesic to slightly dry soil. This plant flourishes best in poor soil that is either gravelly or sandy. It doesn't tolerate much competition from taller plants. Foliar disease is not a significant problem during the period of active growth and blooming, after which this plant will fade away.
Range & Habitat: The native Venus' Looking Glass is fairly common in the southern half of Illinois, but uncommon or absent in many areas of the northern half (see Distribution Map). Habitats include mesic to slightly dry sand prairies, gravel prairies, upland areas of black soil prairies, sandy savannas, lake borders, abandoned fields, and areas along railroads and roadsides, especially where it is gravelly or sandy. The habitats where this plant occurs have sparser and lower vegetation than many other areas as a result of poor soil or disturbance.
Faunal Associations: Small bees are the most common visitors of the flowers. This includes Little Carpenter bees, Plasterer bees, Green Metallic bees, and other Halictine bees. The Plasterer bee Colletes brevicornis is an oligolege of Venus' Looking Glass. Other insect visitors include bumblebees, flies, small butterflies, and skippers. The seeds are too small to be of any interest to birds. Mammalian herbivores may consume this plant, although it is of minor importance as a food source.
Photographic Location: The photographs were taken in a waste area along a gravel road near Champaign, Illinois.
Comments: When it is sunny, the flowers open up during the morning, and remain open for the rest of the day. They are attractive, but rather small. The common name of this plant probably refers to the shiny seeds of a related European species. The seeds of Venus' Looking Glass are too tiny to appear shiny to the unaided human eye. In form and color, the flowers of this plant resemble the flowers of Campanula americana (Tall Bellflower), but the former are much smaller. An older scientific name for this plant is Specularia perfoliata.
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Miss Chen
2018年02月25日
Description: This is a herbaceous perennial plant about 2-4' tall and mostly unbranched, except toward the apex. The central stem is round, glabrous, and occasionally glaucous. The grey- or blue-green alternate leaves are up to 15" long and 1" across. They are linear, although wider at the base, where the leaves wrap around the stem in sheaths, than at the tip. They are also glabrous, with parallel venation and smooth margins, tending to bend downward towards the middle. The light violet to blue-violet flowers occur in small clusters on hairless flowering stems at the top of the plant. Underneath each inflorescence are 2 small bracts, each up to 3" long and less than ½" across. Each flower is about 1" across, with 3 rounded petals, 6 bright yellow anthers, and fine spidery violet hairs near the base. The flowers open up during the morning and close by the afternoon in sunny weather, but remain open longer on cloudy days. There is no floral scent.
The blooming period occurs from late spring to mid-summer, and lasts about 1½ months, during which time only a few flowers are in bloom at the same time. The mature seed capsules split into 3 sections, each capsule releasing 3-6 oval to oblong, brown seeds. The root system is thick, fleshy, and fibrous, sending off occasional offshoots nearby.
Cultivation: The preference is full or partial sun, and moist to slightly dry conditions. The soil can contain loam, clay, gravel, or sand – this plant is very adaptable. Sometimes the leaves develop brown blotches or turn yellow in response to harsh weather conditions, competition from other plants, or age.
Range & Habitat: The native Ohio Spiderwort is a common plant throughout Illinois, except in the SE, where it is uncommon or absent (see Distribution Map). It is often found in moist to mesic black soil prairies and sand prairies. Other habitats include sandy black oak savannas, Bur Oak savannas, limestone glades, thickets and woodland borders, moist meadows near woods or rivers, roadside ditches, and areas along railroads (including the ballast). Plants are usually widely scattered, but sometimes appear in sizable colonies in disturbed areas.
Faunal Associations: The most important pollinators of the flowers are long-tongued bees, especially bumblebees. Other visitors include Halictine bees and Syrphid flies. However, the Syrphid flies feed on stray pollen and are non-pollinating. Spiderwort is rarely bothered by insects, although Lema collaris (Leaf Beetle sp.) reportedly feeds on the foliage. Mammalian herbivores also eat the plant, including the White-Tailed Deer, Cottontail Rabbit, Box Turtles, and livestock. The foliage is non-toxic to these animals.
Photographic Location: The close-up photograph of the flowers was taken along a railroad in Champaign, Illinois, while the photographs of the flowering plant and close-up of the stem were taken at the wildflower garden of the webmaster in Urbana, Illinois. Ohio Spiderwort is more resistant to the application of herbicides along railroads than most plants, which is one reason why it remains common in such areas.
Comments: This is probably the most common Spiderwort in Illinois. The flowers are short-lived, but beautiful, particularly when they are viewed close-up. Ohio Spiderwort can be readily distinguished from Virginia Spiderwort by the absence of conspicuous hairs on the flowering stems near the inflorescence, and the greyish or bluish appearance of the thin leaves. It also tends to be taller and more spindly in appearance than other species of Spiderwort, and has smaller bracts subtending the inflorescence. The leaves and stems are reported to be edible – fresh or cooked.
The blooming period occurs from late spring to mid-summer, and lasts about 1½ months, during which time only a few flowers are in bloom at the same time. The mature seed capsules split into 3 sections, each capsule releasing 3-6 oval to oblong, brown seeds. The root system is thick, fleshy, and fibrous, sending off occasional offshoots nearby.
Cultivation: The preference is full or partial sun, and moist to slightly dry conditions. The soil can contain loam, clay, gravel, or sand – this plant is very adaptable. Sometimes the leaves develop brown blotches or turn yellow in response to harsh weather conditions, competition from other plants, or age.
Range & Habitat: The native Ohio Spiderwort is a common plant throughout Illinois, except in the SE, where it is uncommon or absent (see Distribution Map). It is often found in moist to mesic black soil prairies and sand prairies. Other habitats include sandy black oak savannas, Bur Oak savannas, limestone glades, thickets and woodland borders, moist meadows near woods or rivers, roadside ditches, and areas along railroads (including the ballast). Plants are usually widely scattered, but sometimes appear in sizable colonies in disturbed areas.
Faunal Associations: The most important pollinators of the flowers are long-tongued bees, especially bumblebees. Other visitors include Halictine bees and Syrphid flies. However, the Syrphid flies feed on stray pollen and are non-pollinating. Spiderwort is rarely bothered by insects, although Lema collaris (Leaf Beetle sp.) reportedly feeds on the foliage. Mammalian herbivores also eat the plant, including the White-Tailed Deer, Cottontail Rabbit, Box Turtles, and livestock. The foliage is non-toxic to these animals.
Photographic Location: The close-up photograph of the flowers was taken along a railroad in Champaign, Illinois, while the photographs of the flowering plant and close-up of the stem were taken at the wildflower garden of the webmaster in Urbana, Illinois. Ohio Spiderwort is more resistant to the application of herbicides along railroads than most plants, which is one reason why it remains common in such areas.
Comments: This is probably the most common Spiderwort in Illinois. The flowers are short-lived, but beautiful, particularly when they are viewed close-up. Ohio Spiderwort can be readily distinguished from Virginia Spiderwort by the absence of conspicuous hairs on the flowering stems near the inflorescence, and the greyish or bluish appearance of the thin leaves. It also tends to be taller and more spindly in appearance than other species of Spiderwort, and has smaller bracts subtending the inflorescence. The leaves and stems are reported to be edible – fresh or cooked.
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Miss Chen
2018年02月25日
Description: This annual plant is about ½–2½' tall and unbranched. The central stem is round and has numerous white hairs. The opposite leaves are about 2" long and ¾" across. They are broadly lanceolate and sessile against the stem, with smooth margins and fine white hairs covering the upper and lower surfaces. Each of the upper leaves usually have two small lobes at the base, which resemble ears. The inflorescence consists of a spike of flowers in the upper half of the plant. These flowers are purple, pinkish purple, or lavender. Each tubular flower is about ¾" long, with 5 short lobes that flare outward. Sometimes there are purple dots inside the corolla. The reproductive parts consist of 4 stamens and 1 stigma near the upper inner surface of the corolla. Each flower is subtended by a large green calyx that is hairy and divided into 5 triangular parts. The blooming period occurs during late summer and lasts about 3 weeks. A fruit develops within each calyx that contains numerous small seeds. At this time, the entire plant becomes reddish brown. These seeds are probably distributed by the wind to some extent. The root system consists of a central taproot and secondary roots – the latter are often parasitic on the roots of other plants. However, in the absence of a suitable host, Ear-Leaved False Foxglove can meet its own needs adequately through photosynthesis.
Cultivation: The preference is full or partial sun and mesic conditions. This plant typically grows in rich, loamy soil. It appears to have few problems with disease. The seeds can be slow to germinate; it is possible that a heat treatment simulating the effects of a wildfire may be beneficial in this regard.
Range & Habitat: Ear-Leaved False Foxglove is a rare plant that occurs in scattered counties throughout most of Illinois, except the extreme south (see Distribution Map). It is a native plant that is state-listed as 'threatened.' Habitats include mesic black soil prairies, thickets containing grasses and occasional shrubs, savannas, woodland borders, abandoned fields, and areas along railroads (particularly where remnant prairies occur). This plant is found in both high quality habitats and somewhat disturbed areas. It is intolerant of frequent mowing or grazing; however an occasional wildfire may improve germination of the seeds, as well as reducing competition from shrubs and other kinds of plants.
Faunal Associations: Bumblebees are the most important pollinators of the flowers, where they seek nectar. Other long-tongued bees also visit the flowers, including miner bees and leaf-cutting bees. Little information is available about this plant's relationship to mammalian herbivores; because the foliage is not known to be toxic, it is probably consumed by them occasionally.
Photographic Location: The photograph of the plant in flower was taken by Lisa Culp (Copyright © 2009) at a nature preserve in Cook County, Illinois, while the lower photograph was taken by the webmaster at a prairie remnant along a railroad in Iroquois County, Illinois.
Comments: This wildflower is easy to identify because of the small basal lobes on some of its leaves. It is closely related to the purple-flowered Agalinis spp., which are also partially parasitic on other plants. In addition to its peculiar basal lobes, Ear-Leaved False Foxglove has wider leaves than the latter species.
Cultivation: The preference is full or partial sun and mesic conditions. This plant typically grows in rich, loamy soil. It appears to have few problems with disease. The seeds can be slow to germinate; it is possible that a heat treatment simulating the effects of a wildfire may be beneficial in this regard.
Range & Habitat: Ear-Leaved False Foxglove is a rare plant that occurs in scattered counties throughout most of Illinois, except the extreme south (see Distribution Map). It is a native plant that is state-listed as 'threatened.' Habitats include mesic black soil prairies, thickets containing grasses and occasional shrubs, savannas, woodland borders, abandoned fields, and areas along railroads (particularly where remnant prairies occur). This plant is found in both high quality habitats and somewhat disturbed areas. It is intolerant of frequent mowing or grazing; however an occasional wildfire may improve germination of the seeds, as well as reducing competition from shrubs and other kinds of plants.
Faunal Associations: Bumblebees are the most important pollinators of the flowers, where they seek nectar. Other long-tongued bees also visit the flowers, including miner bees and leaf-cutting bees. Little information is available about this plant's relationship to mammalian herbivores; because the foliage is not known to be toxic, it is probably consumed by them occasionally.
Photographic Location: The photograph of the plant in flower was taken by Lisa Culp (Copyright © 2009) at a nature preserve in Cook County, Illinois, while the lower photograph was taken by the webmaster at a prairie remnant along a railroad in Iroquois County, Illinois.
Comments: This wildflower is easy to identify because of the small basal lobes on some of its leaves. It is closely related to the purple-flowered Agalinis spp., which are also partially parasitic on other plants. In addition to its peculiar basal lobes, Ear-Leaved False Foxglove has wider leaves than the latter species.
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Miss Chen
2018年02月24日
Description: This is a perennial plant that branches sparingly, and it is up to 3½' tall. The alternate leaves are bipinnately or ternately compound, and tend to be aggregated toward the base of the plant. The basal leaves are up to 12" long and 6" across, while smaller leaves are sparsely distributed along the middle and upper portions of the stems. Sometimes there are minute stiff hairs at the base of the petioles where the compound leaves meet the stem. The leaflets have large blunt teeth, and often occur in pairs or triplets, with the terminal leaflets achieving the largest size. Each leaflet is up to 1" long and ½" across, lanceolate or ovate, and has wedge-shaped lower margins. The overall appearance of the leaves resembles Italian Parsley.
Flowering Plant in Prairie
Rounded compound umbels of light yellow flowers occur at the ends of the central stem and major side stems. Each umbel is about 3" across, and is composed of 12-20 umbellets. Each umbellet consists of a similar number of tiny flowers, each one with 5 petals. There is no noticeable floral scent. The blooming period occurs during the late spring or early summer, and lasts about a month. The root system consists of a central taproot.
Cultivation: The preference is full or partial sun and mesic conditions. The soil can contain significant amounts of loam, sand, or rocky material. Light shade is tolerated, but growth will be less robust and flowering less abundant. Hairy-Jointed Meadow Parsnip develops rapidly during the spring, and is usually taller than the surrounding plants when the blooming period begins. After flowering, the condition of the plant rapidly deteriorates.
Range & Habitat: This native plant occurs occasionally in scattered counties of Illinois. Its distribution is oddly bifurcated, consisting primarily of counties in east-central and west-central Illinois (see Distribution Map). Habitats include mesic black soil prairies, openings in forests and woodland borders, sandy savannas, rocky bluffs, and the borders of lakes. This plant occurs in prairies to a greater extent than has been realized in the past.
Faunal Associations: Many kinds of insects are attracted to the flowers, especially short-tongued bees, wasps, flies, and beetles. The caterpillars of the butterfly Papilio polyxenes asterias (Black Swallowtail) feed on the foliage and flowers. This plant is not known to be toxic, and is probably consumed occasionally by various mammalian herbivores, although information about this is limited.
Photographic Location: The photographs of the flowering plant and compound leaf were taken at Loda Cemetery Prairie in Iroquois County, Illinois. The photograph of the umbels and upper leaves was taken at a woodland in Vermilion County, Illinois.
Comments: This native member of the Carrot family should be grown more often in wildflower gardens. Sometimes it is called 'Hairy Meadow Parnsip,' but conspicuous hairs occur only at the base of the petioles of compound leaves, and these are not easy to see unless you know where to look. This plant resembles the weedy and aggressive Pastinaca sativa (Wild Parsnip), but the latter has flat compound umbels of yellow flowers, while Hairy-Jointed Meadow Parsnip has compound umbels of pale yellow flowers that are more rounded. There are also significant differences in the structure of the compound leaves between these two species.
Flowering Plant in Prairie
Rounded compound umbels of light yellow flowers occur at the ends of the central stem and major side stems. Each umbel is about 3" across, and is composed of 12-20 umbellets. Each umbellet consists of a similar number of tiny flowers, each one with 5 petals. There is no noticeable floral scent. The blooming period occurs during the late spring or early summer, and lasts about a month. The root system consists of a central taproot.
Cultivation: The preference is full or partial sun and mesic conditions. The soil can contain significant amounts of loam, sand, or rocky material. Light shade is tolerated, but growth will be less robust and flowering less abundant. Hairy-Jointed Meadow Parsnip develops rapidly during the spring, and is usually taller than the surrounding plants when the blooming period begins. After flowering, the condition of the plant rapidly deteriorates.
Range & Habitat: This native plant occurs occasionally in scattered counties of Illinois. Its distribution is oddly bifurcated, consisting primarily of counties in east-central and west-central Illinois (see Distribution Map). Habitats include mesic black soil prairies, openings in forests and woodland borders, sandy savannas, rocky bluffs, and the borders of lakes. This plant occurs in prairies to a greater extent than has been realized in the past.
Faunal Associations: Many kinds of insects are attracted to the flowers, especially short-tongued bees, wasps, flies, and beetles. The caterpillars of the butterfly Papilio polyxenes asterias (Black Swallowtail) feed on the foliage and flowers. This plant is not known to be toxic, and is probably consumed occasionally by various mammalian herbivores, although information about this is limited.
Photographic Location: The photographs of the flowering plant and compound leaf were taken at Loda Cemetery Prairie in Iroquois County, Illinois. The photograph of the umbels and upper leaves was taken at a woodland in Vermilion County, Illinois.
Comments: This native member of the Carrot family should be grown more often in wildflower gardens. Sometimes it is called 'Hairy Meadow Parnsip,' but conspicuous hairs occur only at the base of the petioles of compound leaves, and these are not easy to see unless you know where to look. This plant resembles the weedy and aggressive Pastinaca sativa (Wild Parsnip), but the latter has flat compound umbels of yellow flowers, while Hairy-Jointed Meadow Parsnip has compound umbels of pale yellow flowers that are more rounded. There are also significant differences in the structure of the compound leaves between these two species.
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Miss Chen
2018年02月24日
Description: This perennial plant is 3-7' tall, branching occasionally. The central stem is rather stout, green or reddish purple, and glaucous or slightly pubescent. The alternate leaves are ternately compound: A primary compound leaf divides into 3 secondary compound leaves, while each secondary compound leaf has 3 leaflets. Each leaflet is about ¾–2" long and half as much across. It is rounded at the base, and either unlobed or with 2-3 lobes toward the outer edge (usually a large middle lobe and 2 smaller side lobes). The margin of each leaflet turns downward slightly. The light green or white lower surface has a waxy appearance that is covered with glandular hairs. These hairs will glisten when they are exposed to sunlight. The lower surface of a leaflet also has a reticulated network of conspicuous veins. The foliage, when crushed in the hand, will produce a skunk-like smell.
Female Plant with Immature Fruits
Occasionally, the upper stems will produce panicles of flowers that are up to 2' long and about half as much across. Individual plants are usually unisexual, producing either male or female flowers. A male flower has 4-5 light green sepals that spread outward, while conspicuous white stamens with yellow or brown anthers occupy the center. Each male flower is about 1/3" long. The male flowers usually droop downward from slender pedicels, and together have an airy appearance that is rather pleasant. The female flowers are shaped like small green burs and have numerous short pistils. They are less attractive than the male flowers. The blooming period is from late spring to early summer, and lasts about 3 weeks. There is no floral scent. Pollination is by wind. The flowers are replaced by small achenes that are ribbed and pointed at both ends. The root system has rhizomes, which enables vegetative colonies to form. This plant gradually dies down during the summer, but forms new vegetation at the base during the fall.
Cultivation: The preference is moist to slight dry conditions, and partial to full sun. This plant usually grows in fairly typical garden soil, such as a rich loam or clay loam. The height of a plant can vary considerably depending on fertility of the soil, moisture conditions, and maturity. Vegetative growth is very rapid during the spring. This species of Meadow Rue appears to tolerate full sun and droughty conditions better than most.
Range & Habitat: Waxy Meadow Rue is widely distributed in Illinois, where it is native. This plant occurs occasionally in central and northern Illinois, but it is less common or absent in southern Illinois (see Distribution Map). Habitats include mesic black soil prairies, thickets and woodland borders, savannas, and areas along railroads and roadsides, especially where remnant prairies occur.
Faunal Associations: Because the flowers are wind-pollinated, few insects visit the flowers. Occasionally bees gather pollen from the anthers of the male flowers, while various kinds of beetles eat the pollen. Because the foliage has a foul scent, it probably is not a preferred food source for mammalian herbivores.
Photographic Location: The photographs were taken at the Red Bison Railroad Prairie in Savoy, Illinois. The plants were growing in full sunlight under mesic conditions.
Comments: This plant is reasonably attractive while in bloom, but this doesn't last very long. The various Thalictrum spp. have very similar flowers, but can be distinguished by their foliage. Waxy Meadow Rue has glandular hairs on the undersides of the leaflets (which glisten in the sunlight), and the foliage has a foul scent when it is crushed. Another species, Thalictrum dasycarpum (Purple Meadow Rue), has a very similar appearance, but the hairs on the undersides of the leaflets (if present) are non-glandular, while the foliage has little scent. Either of these plants can occur in prairies. Another species that is fairly common in Illinois, Thalictrum dioicum (Early Meadow Rue), is a shorter plant that blooms earlier and occurs in woodlands. However, the terminal leaflets of this species have 5 lobes toward the outer margin, while the terminal leaflets of Waxy and Purple Meadow Rue have only 3 lobes.
Female Plant with Immature Fruits
Occasionally, the upper stems will produce panicles of flowers that are up to 2' long and about half as much across. Individual plants are usually unisexual, producing either male or female flowers. A male flower has 4-5 light green sepals that spread outward, while conspicuous white stamens with yellow or brown anthers occupy the center. Each male flower is about 1/3" long. The male flowers usually droop downward from slender pedicels, and together have an airy appearance that is rather pleasant. The female flowers are shaped like small green burs and have numerous short pistils. They are less attractive than the male flowers. The blooming period is from late spring to early summer, and lasts about 3 weeks. There is no floral scent. Pollination is by wind. The flowers are replaced by small achenes that are ribbed and pointed at both ends. The root system has rhizomes, which enables vegetative colonies to form. This plant gradually dies down during the summer, but forms new vegetation at the base during the fall.
Cultivation: The preference is moist to slight dry conditions, and partial to full sun. This plant usually grows in fairly typical garden soil, such as a rich loam or clay loam. The height of a plant can vary considerably depending on fertility of the soil, moisture conditions, and maturity. Vegetative growth is very rapid during the spring. This species of Meadow Rue appears to tolerate full sun and droughty conditions better than most.
Range & Habitat: Waxy Meadow Rue is widely distributed in Illinois, where it is native. This plant occurs occasionally in central and northern Illinois, but it is less common or absent in southern Illinois (see Distribution Map). Habitats include mesic black soil prairies, thickets and woodland borders, savannas, and areas along railroads and roadsides, especially where remnant prairies occur.
Faunal Associations: Because the flowers are wind-pollinated, few insects visit the flowers. Occasionally bees gather pollen from the anthers of the male flowers, while various kinds of beetles eat the pollen. Because the foliage has a foul scent, it probably is not a preferred food source for mammalian herbivores.
Photographic Location: The photographs were taken at the Red Bison Railroad Prairie in Savoy, Illinois. The plants were growing in full sunlight under mesic conditions.
Comments: This plant is reasonably attractive while in bloom, but this doesn't last very long. The various Thalictrum spp. have very similar flowers, but can be distinguished by their foliage. Waxy Meadow Rue has glandular hairs on the undersides of the leaflets (which glisten in the sunlight), and the foliage has a foul scent when it is crushed. Another species, Thalictrum dasycarpum (Purple Meadow Rue), has a very similar appearance, but the hairs on the undersides of the leaflets (if present) are non-glandular, while the foliage has little scent. Either of these plants can occur in prairies. Another species that is fairly common in Illinois, Thalictrum dioicum (Early Meadow Rue), is a shorter plant that blooms earlier and occurs in woodlands. However, the terminal leaflets of this species have 5 lobes toward the outer margin, while the terminal leaflets of Waxy and Purple Meadow Rue have only 3 lobes.
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Miss Chen
2018年02月24日
Description: This herbaceous perennial plant is ½–2' tall, producing one or more leafy stems that are erect, ascending, or sprawling. The wiry stems branch sparingly, and they are often curved, arching, or crooked. Young stems are whitish green to silver-colored and terete; they are moderately to densely covered with fine pubescence. Older stems are brown or purple and sparsely to moderately covered with fine pubescence. Alternate leaves occur along the entire length of each stem, becoming slightly smaller in size as they ascend. The leaves are ½–1¼" long and about 4-8 mm. across; they are oblong to elliptic in shape and entire (smooth) along their margins. The bases of leaves are sessile or clasp their stems slightly, while the tips of leaves are short-acute. Both the upper and lower surfaces of leaves are whitish green to silver-colored; they are moderately to densely covered with appressed fine pubescence. The upper stems terminate in one or more flowerheads. On a robust plant, this inflorescence resembles a little-branched open panicle up to ¾' long that has 6-18 flowerheads, otherwise the inflorescence consists of 1-2 short branches with 1-3 flowerheads at their tips or slightly below.
The wiry branches of the inflorescence are terete, whitish green to silver-colored, and moderately to densely covered with fine pubescence. Along the branches of larger inflorescences, there are leafy bracts that resemble the alternate leaves. The daisy-like flowerheads are about 1¼" across, consisting of 10-22 ray florets that surround numerous disk florets. The petaloid rays of the flowerheads are linear-oblong in shape, widely spreading, and lavender, deep lavender, or various shades of purple. The tiny corollas of the disk florets are tubular in shape with 5 lanceolate lobes along their upper rims; these lobes are erect to ascending. During the period of bloom, the corollas of the disk florets are white to pale pinkish purple; their anther tubes are yellow and their stigmas are lavender to purple. The blooming period occurs from late summer into autumn, lasting about 1 month for a colony of plants. Afterwards, the florets are replaced by achenes. These achenes are 2-3 mm. long and bullet-shaped with small tufts of hair at their apices; they are dispersed by the wind. The root system is fibrous and occasionally rhizomatous; older plants form short caudices. Occasionally, clonal offsets are produced from rhizomes.
Cultivation: The preference is full sun and mesic to dry conditions. Almost any kind of soil is satisfactory if the site is well-drained, but this plant typically grows in poor soil that is rocky or sandy. A high pH is tolerated. Overall, this plant develops more slowly than most perennial asters (Symphyotrichum spp.) and it is a bit more difficult to grow. It doesn't tolerate much competition from taller ground vegetation. While the drought tolerance of mature plants is good, some of the lower leaves will wither away and fall from the stems.
Range & Habitat: The native Silky Aster occurs primarily in the northern tier of counties and in many counties along the Illinois and Mississippi Rivers (see Distribution Map). It is an uncommon plant that appears to be declining in abundance as a result of habitat destruction. These habitats include upland dolomite prairies, gravel prairies, sand prairies, hill prairies, stabilized sand dunes, upland sandy savannas, limestone glades, and prairie remnants along railroads. This is an indicator plant of high quality habitats in dry open areas.
Faunal Associations: The nectar and pollen of the flowerheads attract bumblebees, leaf-cutting bees (Megachile spp.), green metallic bees (Agapostemon spp.), Syrphid flies, and small- to medium-sized butterflies, including the endangered Karner Blue (Lycaeides melissa samuelis); see Reed (1993) and Swengel & Swengel (2000). Syrphid flies are probably non-pollinating. A plant bug, Psallus astericola, feeds on Silky Aster (Knight, 1941). Other insects that feed of the foliage and other parts of asters (Symphyotrichum spp.) include leaf beetles, the larvae of leaf-mining flies, the larvae of gall flies, other plant bugs, aphids, the larvae of moths, the larvae of butterflies, and grasshoppers. Among mammals, the young foliage of these plants are browsed occasionally by rabbits, deer, groundhogs, cattle, horses, and sheep. However, Silky Aster may be an exception to this rule, as it was found to increase in abundance as a result of grazing (Brudvig et al., 2007). Among birds, the Wild Turkey also browses on the foliage of asters; this upland gamebird and the Tree Sparrow also eat their seeds (Martin et al., 1951/1961).
Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois.
Comments: This is a truly beautiful little plant with attractive foliage and flowerheads. It's an excellent candidate as a wildflower in a sunny rock garden. In Illinois, Silky Aster (Symphyotrichum sericeum) can be distinguished from all other asters (Symphyotrichum spp.) within the state by its exceptional foliage, which has a silvery or silky appearance because of the numerous fine hairs covering its stems and leaves. It also has larger flowerheads (often exceeding 1" across) than most native or naturalized species of asters within the state. A scientific synonym of this plant is Aster sericeus.
The wiry branches of the inflorescence are terete, whitish green to silver-colored, and moderately to densely covered with fine pubescence. Along the branches of larger inflorescences, there are leafy bracts that resemble the alternate leaves. The daisy-like flowerheads are about 1¼" across, consisting of 10-22 ray florets that surround numerous disk florets. The petaloid rays of the flowerheads are linear-oblong in shape, widely spreading, and lavender, deep lavender, or various shades of purple. The tiny corollas of the disk florets are tubular in shape with 5 lanceolate lobes along their upper rims; these lobes are erect to ascending. During the period of bloom, the corollas of the disk florets are white to pale pinkish purple; their anther tubes are yellow and their stigmas are lavender to purple. The blooming period occurs from late summer into autumn, lasting about 1 month for a colony of plants. Afterwards, the florets are replaced by achenes. These achenes are 2-3 mm. long and bullet-shaped with small tufts of hair at their apices; they are dispersed by the wind. The root system is fibrous and occasionally rhizomatous; older plants form short caudices. Occasionally, clonal offsets are produced from rhizomes.
Cultivation: The preference is full sun and mesic to dry conditions. Almost any kind of soil is satisfactory if the site is well-drained, but this plant typically grows in poor soil that is rocky or sandy. A high pH is tolerated. Overall, this plant develops more slowly than most perennial asters (Symphyotrichum spp.) and it is a bit more difficult to grow. It doesn't tolerate much competition from taller ground vegetation. While the drought tolerance of mature plants is good, some of the lower leaves will wither away and fall from the stems.
Range & Habitat: The native Silky Aster occurs primarily in the northern tier of counties and in many counties along the Illinois and Mississippi Rivers (see Distribution Map). It is an uncommon plant that appears to be declining in abundance as a result of habitat destruction. These habitats include upland dolomite prairies, gravel prairies, sand prairies, hill prairies, stabilized sand dunes, upland sandy savannas, limestone glades, and prairie remnants along railroads. This is an indicator plant of high quality habitats in dry open areas.
Faunal Associations: The nectar and pollen of the flowerheads attract bumblebees, leaf-cutting bees (Megachile spp.), green metallic bees (Agapostemon spp.), Syrphid flies, and small- to medium-sized butterflies, including the endangered Karner Blue (Lycaeides melissa samuelis); see Reed (1993) and Swengel & Swengel (2000). Syrphid flies are probably non-pollinating. A plant bug, Psallus astericola, feeds on Silky Aster (Knight, 1941). Other insects that feed of the foliage and other parts of asters (Symphyotrichum spp.) include leaf beetles, the larvae of leaf-mining flies, the larvae of gall flies, other plant bugs, aphids, the larvae of moths, the larvae of butterflies, and grasshoppers. Among mammals, the young foliage of these plants are browsed occasionally by rabbits, deer, groundhogs, cattle, horses, and sheep. However, Silky Aster may be an exception to this rule, as it was found to increase in abundance as a result of grazing (Brudvig et al., 2007). Among birds, the Wild Turkey also browses on the foliage of asters; this upland gamebird and the Tree Sparrow also eat their seeds (Martin et al., 1951/1961).
Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois.
Comments: This is a truly beautiful little plant with attractive foliage and flowerheads. It's an excellent candidate as a wildflower in a sunny rock garden. In Illinois, Silky Aster (Symphyotrichum sericeum) can be distinguished from all other asters (Symphyotrichum spp.) within the state by its exceptional foliage, which has a silvery or silky appearance because of the numerous fine hairs covering its stems and leaves. It also has larger flowerheads (often exceeding 1" across) than most native or naturalized species of asters within the state. A scientific synonym of this plant is Aster sericeus.
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Miss Chen
2018年02月23日
Description: This herbaceous perennial plant is 2-5' tall, branching occasionally. The larger stems are occasionally reddish, and have lines of white hairs. The alternate leaves are up to 5½" long and ¾" across, becoming smaller and narrower as they ascend up the stems. They are lanceolate, narrowly ovate, or linear, and have smooth margins. Underneath, the leaves are whitish green with a reticulate network of fine veins that is quite conspicuous.
The inflorescence is large and pyramidal, containing numerous daisy-like composite flowers from ½–¾" across. Each flower has 20-30 lavender or light blue ray florets surrounding numerous yellow disk florets that eventually become reddish purple. The blooming period occurs from early to mid-fall, and lasts about a month. There is no noticeable floral scent. The achenes develop with small tufts of hair, and are dispersed by the wind. The root system is fibrous and rhizomatous. The Willow Aster often spreads vegetatively to form small to large colonies.
Cultivation: The preference is full sun, moist conditions, and fertile loamy soil. Foliar disease occurs occasionally, which may involve some yellowing of the leaves and the formation of black spots. This affects primarily the older leaves near the base of the plant, otherwise the foliage remains attractive. Some standing water is tolerated if it is temporary.
Range & Habitat: The native Willow Aster is widely distributed, and it occurs in most counties of Illinois (see Distribution Map). This plant is occasional to locally common. Habitats include moist black soil prairies, moist meadows along rivers and lakes, thickets, roadside ditches, abandoned fields, and other poorly drained areas.
Faunal Associations: Many kinds of insects visit the flowers, including long-tongued bees, short-tongued bees, flies, butterflies, and skippers. Among the bees, this includes such visitors as honeybees, bumblebees, Halictine bees, and some Andrenid bees that fly late in the season. Some Syrphid flies and beetles may feed on the pollen, otherwise these insects seek nectar; bees also collect pollen for their larvae. The caterpillars of the butterflies Chlosyne nycteis (Silvery Checkerspot) Phyciodes tharos (Pearl Crescent) feed on the foliage, as well as the caterpillars of several species of moths (see Moth Table). Various insects suck the juices from this and other asters, including plant bugs, lace bugs, and aphids. The Wild Turkey eats the foliage and seeds to a limited extent. Deer browse on this plant occasionally, while rabbits nibble on the foliage of immature plants.
Photographic Location: The photographs were taken at Loda Cemetery Prairie in Iroquois County, Illinois.
Comments: This is another attractive aster for autumn bloom, producing abundant flowers. The Willow Aster can be distinguished from other asters (Symphyotrichum spp.) by the conspicuous reticulated pattern on the lower surface of its leaves. In addition, the stalks of the flowerheads are relatively short and they are covered with relatively large leafy bracts. Unlike many woodland asters, the leaves of Willow Aster are always narrow and willow-like, even at the base of the plant, and they lack serrated edges. The flowers are usually lavender or light violet, although sometimes they are white.
The inflorescence is large and pyramidal, containing numerous daisy-like composite flowers from ½–¾" across. Each flower has 20-30 lavender or light blue ray florets surrounding numerous yellow disk florets that eventually become reddish purple. The blooming period occurs from early to mid-fall, and lasts about a month. There is no noticeable floral scent. The achenes develop with small tufts of hair, and are dispersed by the wind. The root system is fibrous and rhizomatous. The Willow Aster often spreads vegetatively to form small to large colonies.
Cultivation: The preference is full sun, moist conditions, and fertile loamy soil. Foliar disease occurs occasionally, which may involve some yellowing of the leaves and the formation of black spots. This affects primarily the older leaves near the base of the plant, otherwise the foliage remains attractive. Some standing water is tolerated if it is temporary.
Range & Habitat: The native Willow Aster is widely distributed, and it occurs in most counties of Illinois (see Distribution Map). This plant is occasional to locally common. Habitats include moist black soil prairies, moist meadows along rivers and lakes, thickets, roadside ditches, abandoned fields, and other poorly drained areas.
Faunal Associations: Many kinds of insects visit the flowers, including long-tongued bees, short-tongued bees, flies, butterflies, and skippers. Among the bees, this includes such visitors as honeybees, bumblebees, Halictine bees, and some Andrenid bees that fly late in the season. Some Syrphid flies and beetles may feed on the pollen, otherwise these insects seek nectar; bees also collect pollen for their larvae. The caterpillars of the butterflies Chlosyne nycteis (Silvery Checkerspot) Phyciodes tharos (Pearl Crescent) feed on the foliage, as well as the caterpillars of several species of moths (see Moth Table). Various insects suck the juices from this and other asters, including plant bugs, lace bugs, and aphids. The Wild Turkey eats the foliage and seeds to a limited extent. Deer browse on this plant occasionally, while rabbits nibble on the foliage of immature plants.
Photographic Location: The photographs were taken at Loda Cemetery Prairie in Iroquois County, Illinois.
Comments: This is another attractive aster for autumn bloom, producing abundant flowers. The Willow Aster can be distinguished from other asters (Symphyotrichum spp.) by the conspicuous reticulated pattern on the lower surface of its leaves. In addition, the stalks of the flowerheads are relatively short and they are covered with relatively large leafy bracts. Unlike many woodland asters, the leaves of Willow Aster are always narrow and willow-like, even at the base of the plant, and they lack serrated edges. The flowers are usually lavender or light violet, although sometimes they are white.
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Miss Chen
2018年02月23日
Description: This herbaceous perennial plant is 1½–3' tall and largely unbranched, except near the inflorescence. The central stem is light green, terete, and glabrous to sparsely short-hairy. Alternate leaves occur along the central stem, becoming shorter and more narrow as they ascend. The lower leaves are up to 3" long and 1½" across; they are narrowly oval to ovate in shape and smooth along their margins. The middle leaves are up to 2½" long and ¾" across; they are narrowly lanceolate to lanceolate in shape and smooth along their margins. The upper leaves are up to 1¼" long and ¼" across; they are linear-oblong in shape and smooth along their margins. The upper leaf surfaces are medium to dark green and glabrous or nearly so, while their lower surfaces are light green and glabrous to short-hairy along the major veins. The petioles of these leaves are up to 2" long, becoming shorter as they ascend the stem – however the upper leaves are sessile. The petioles are light green, concave above and convex below, and glabrous to slightly hairy. In addition to the deciduous alternate leaves, this plant also produces a loose tuft of semi-evergreen basal leaves. These basal leaves are similar in appearance to the lower alternate leaves, except they are more broad (oval to oval-cordate in shape) and their margins are sometimes crenate-serrate. The petioles of basal leaves are up to 3" long. The central stem terminates in a panicle of flowerheads that is ½–1½' long and about one-half as much across. When a plant is in bloom, it often leans to one side because of the weight of the inflorescence.
Several Flowerheads
The panicle has a rachis (central stalk) and several ascending primary branches; these branches divide into secondary and tertiary branches that terminate in daisy-like flowerheads. The rachis and branches are light green and glabrous to sparsely short-hairy; scale-like to linear leafy bracts up to ¾" long occur at intervals along these branches. Each flowerhead is about ½" across or slightly larger, consisting of 10-25 ray florets that surround numerous disk florets. The petaloid rays are lavender or light blue (rarely white), linear-oblong in shape, slightly notched at their tips, and widely spreading. The tiny corollas of the disk florets are tubular in shape with 5 ascending to spreading lobes along their upper rims; these corollas are initially yellow, but they later become purplish red and finally brown. Surrounding the base of each flowerhead, there are scale-like bracts (phyllaries) that are arranged in 3-5 series that are appressed together or slightly spreading. These floral bracts are about 2 mm. long, lanceolate in shape, and mostly light green, except toward their tips, where there are dark green patches that are diamond-shaped. The blooming period occurs from late summer into autumn, lasting about 1 month for a colony of plants. Afterwards, the florets are replaced by small bullet-shaped achenes (about 2 mm. in length) that have small tufts of hair at their apices. These achenes are distributed by the wind. The root system is fibrous and rhizomatous; older plants may develop a short caudex.
Cultivation: The preference is full or partial sun and mesic to dry conditions. This plant is rather indifferent to soil characteristics – it can flourish in soil that is loamy, sandy, rocky, or contains clay. This plant is easy to grow and drought resistant; the lower leaves are occasionally marred by powdery mildew and other foliar diseases.
Range & Habitat: The native Sky Blue Aster occurs occasionally in the northern and western halves of Illinois, but it is uncommon or absent elsewhere (see Distribution Map). Habitats include mesic to dry prairies, sand prairies, hill prairies, rocky upland woodlands, upland savannas, upland sandy savannas, woodland borders, sandy meadows, limestone glades, and roadside embankments. This plant is usually found in higher quality natural areas where the original ground flora is still intact. Occasional wildfires or other disturbance that reduce competition from woody vegetation is beneficial in maintaining populations of this plant.
Faunal Associations: For Sky Blue Aster, the nectar and pollen of the flowerheads attract bumblebees, digger bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), Halictid bees (Agapostemon spp., Halictus spp., Lasioglossum spp.), Andrenid bees, Syrphid flies, bee flies (Bombyliidae), butterflies, skippers, miscellaneous beetles, and other insects (Reed, 1993). Bees that are specialist pollinators (oligoleges) of asters (Symphyotrichum spp.) and closely related composites include Andrena asteris, Andrena nubecula, Andrena simplex, Colletes simulans armatus, and Melissodes dentiventris. Other insects feed destructively on the leaves, flowerheads, and other parts of asters. These species include larvae of the Aster Leafminer Fly (Calycomyza humeralis), larvae of the Papery Blister Gall Midge (Asteromyia laeviana), larvae of fruit flies, plant bugs, the Goldenrod Lace Bug (Corythucha marmorata), aphids (especially Uroleucon spp.), the Aster Leafhopper (Macrosteles fascifrons), Blatchley's Walkingstick (Manomera blatchleyi), and grasshoppers (see the Insect Table for a listing of these and other species). In addition, larvae of the butterflies Silvery Checkerspot (Chlosyne nycteis) and Pearl Crescent (Phyciodes tharos) feed on asters, as do larvae of the Aster Borer Moth (Carmenta corni), The Asteroid (Cucullia asteroides), and many other moths (see Moth Table). Among birds, the Ruffed Grouse and Wild Turkey browse on the leaves and seeds of asters; the Tree Sparrow also eats the seeds during the winter. Among mammals, the Cottontail Rabbit and White-Tailed Deer browse on the foliage, while the White-footed Mouse eats the seeds (Martin et al., 1951/1961). Groundhogs, cattle, horses, and other livestock also browse on the foliage, especially when it is young and tender.
Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois.
Comments: For the size of the plant, the inflorescence of Sky Blue Aster (Symphyotrichum oolentangiense) is rather large and showy. This species of aster closely resembles Short's Aster (Symphyotrichum shortii), even though the latter species is a woodland aster. However, the upper leaves of Short's Aster are often narrowly cordate, rather than narrowly lanceolate or linear, and its flowerheads are slightly larger in size. Another similar species, Smooth Blue Aster (Symphyotrichum laeve), has alternate leaves that are all sessile, while Sky Blue Aster has lower to middle leaves with petioles. Other asters (Symphyotrichum spp.) have hairier foliage, or their leaves are narrow throughout, or they have more cordate leaves, or their alternate leaves have toothed margins. Older scientific names for Sky Blue Aster include Aster azureus and Aster oolentangiensis, while another common name for this species is Azure Aster.
Several Flowerheads
The panicle has a rachis (central stalk) and several ascending primary branches; these branches divide into secondary and tertiary branches that terminate in daisy-like flowerheads. The rachis and branches are light green and glabrous to sparsely short-hairy; scale-like to linear leafy bracts up to ¾" long occur at intervals along these branches. Each flowerhead is about ½" across or slightly larger, consisting of 10-25 ray florets that surround numerous disk florets. The petaloid rays are lavender or light blue (rarely white), linear-oblong in shape, slightly notched at their tips, and widely spreading. The tiny corollas of the disk florets are tubular in shape with 5 ascending to spreading lobes along their upper rims; these corollas are initially yellow, but they later become purplish red and finally brown. Surrounding the base of each flowerhead, there are scale-like bracts (phyllaries) that are arranged in 3-5 series that are appressed together or slightly spreading. These floral bracts are about 2 mm. long, lanceolate in shape, and mostly light green, except toward their tips, where there are dark green patches that are diamond-shaped. The blooming period occurs from late summer into autumn, lasting about 1 month for a colony of plants. Afterwards, the florets are replaced by small bullet-shaped achenes (about 2 mm. in length) that have small tufts of hair at their apices. These achenes are distributed by the wind. The root system is fibrous and rhizomatous; older plants may develop a short caudex.
Cultivation: The preference is full or partial sun and mesic to dry conditions. This plant is rather indifferent to soil characteristics – it can flourish in soil that is loamy, sandy, rocky, or contains clay. This plant is easy to grow and drought resistant; the lower leaves are occasionally marred by powdery mildew and other foliar diseases.
Range & Habitat: The native Sky Blue Aster occurs occasionally in the northern and western halves of Illinois, but it is uncommon or absent elsewhere (see Distribution Map). Habitats include mesic to dry prairies, sand prairies, hill prairies, rocky upland woodlands, upland savannas, upland sandy savannas, woodland borders, sandy meadows, limestone glades, and roadside embankments. This plant is usually found in higher quality natural areas where the original ground flora is still intact. Occasional wildfires or other disturbance that reduce competition from woody vegetation is beneficial in maintaining populations of this plant.
Faunal Associations: For Sky Blue Aster, the nectar and pollen of the flowerheads attract bumblebees, digger bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), Halictid bees (Agapostemon spp., Halictus spp., Lasioglossum spp.), Andrenid bees, Syrphid flies, bee flies (Bombyliidae), butterflies, skippers, miscellaneous beetles, and other insects (Reed, 1993). Bees that are specialist pollinators (oligoleges) of asters (Symphyotrichum spp.) and closely related composites include Andrena asteris, Andrena nubecula, Andrena simplex, Colletes simulans armatus, and Melissodes dentiventris. Other insects feed destructively on the leaves, flowerheads, and other parts of asters. These species include larvae of the Aster Leafminer Fly (Calycomyza humeralis), larvae of the Papery Blister Gall Midge (Asteromyia laeviana), larvae of fruit flies, plant bugs, the Goldenrod Lace Bug (Corythucha marmorata), aphids (especially Uroleucon spp.), the Aster Leafhopper (Macrosteles fascifrons), Blatchley's Walkingstick (Manomera blatchleyi), and grasshoppers (see the Insect Table for a listing of these and other species). In addition, larvae of the butterflies Silvery Checkerspot (Chlosyne nycteis) and Pearl Crescent (Phyciodes tharos) feed on asters, as do larvae of the Aster Borer Moth (Carmenta corni), The Asteroid (Cucullia asteroides), and many other moths (see Moth Table). Among birds, the Ruffed Grouse and Wild Turkey browse on the leaves and seeds of asters; the Tree Sparrow also eats the seeds during the winter. Among mammals, the Cottontail Rabbit and White-Tailed Deer browse on the foliage, while the White-footed Mouse eats the seeds (Martin et al., 1951/1961). Groundhogs, cattle, horses, and other livestock also browse on the foliage, especially when it is young and tender.
Photographic Location: The photographs were taken at the webmaster's wildflower garden in Urbana, Illinois.
Comments: For the size of the plant, the inflorescence of Sky Blue Aster (Symphyotrichum oolentangiense) is rather large and showy. This species of aster closely resembles Short's Aster (Symphyotrichum shortii), even though the latter species is a woodland aster. However, the upper leaves of Short's Aster are often narrowly cordate, rather than narrowly lanceolate or linear, and its flowerheads are slightly larger in size. Another similar species, Smooth Blue Aster (Symphyotrichum laeve), has alternate leaves that are all sessile, while Sky Blue Aster has lower to middle leaves with petioles. Other asters (Symphyotrichum spp.) have hairier foliage, or their leaves are narrow throughout, or they have more cordate leaves, or their alternate leaves have toothed margins. Older scientific names for Sky Blue Aster include Aster azureus and Aster oolentangiensis, while another common name for this species is Azure Aster.
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Miss Chen
2018年02月23日
Description: This perennial plant is 1-2' tall, branching frequently to create a bushy appearance. The slender stems are rather stiff and slightly pubescent; the lower stems turn brown and become slightly woody during the fall. The alternate leaves are up to 2" long and ½" across, becoming smaller as they ascend the stems; they are typically one-half the maximum size or a little less. They are linear to linear-oblong, slightly pubescent, and smooth along the slightly ciliate margins. These leaves are rather densely crowded along the stems (particularly the upper stems) and sessile.
The compound flowers are daisy-like and about 1–1¼" across. Each compound flower consists of about 20-35 blue-violet or purple ray florets that surround numerous disk florets that are yellow or amber. These disk florets later become reddish purple. Each compound flower is subtended by spreading linear bracts that resemble the upper leaves. The blooming period occurs during the fall and lasts about 1-2 months; a robust plant will be covered with flowerheads. There is no noticeable floral scent, although the crushed foliage and flowerheads have a balsam-like aroma. Aromatic Aster is one of the last wildflowers to bloom prior to heavy frost. The achenes have small tufts of light brown hair and are distributed by the wind. The root system is fibrous and rhizomatous; older plants often have a short caudex. There can be significant variability in the characteristics of plants across different locations.
Cultivation: The preference is full sun and dry conditions, although an average moisture level is tolerated if the site is well-drained. Poor, rocky soil with open terrain is preferred; a high pH is tolerated. Some of the lower leaves may wither away before the plants begin to bloom, but the foliage usually remains quite attractive. At moist fertile sites, this plant has trouble competing against tall aggressive plants, unless such neighbors are selectively weeded out.
Range & Habitat: The native Aromatic Aster occurs primarily in northern Illinois, the hilly sections of southern Illinois, and in areas bordering the Mississippi and Illinois rivers (see Distribution Map). It is generally an uncommon plant, although locally common at a few exceptional sites. Habitats include mesic to dry gravel prairies, dolomite prairies, gravelly hill prairies, limestone glades, and rocky bluffs along major rivers.
Faunal Associations: Many insects visit the flowers, including long-tongued bees, short-tongued bees, small to medium-sized butterflies, and skippers. These insects seek nectar primarily, although the bees also collect pollen. Many kinds of insects feed on the foliage and other parts of asters, including the caterpillars of the butterfly Chlosyne nycteis (Silvery Checkerspot) and many moth species (see Moth Table). The Wild Turkey and possibly other upland gamebirds eat the seeds and foliage to a limited extent. Mammalian herbivores occasionally eat the foliage of asters, even though their food value is low.
Photographic Location: The above photographs were taken in the wildflower garden of the webmaster in Urbana, Illinois.
Comments: This aster has attractive flowers and is fairly easy to cultivate in a sunny rock garden and similar areas. Aromatic Aster can be distinguished from other asters (Symphyotrichum spp.) by the number of ray florets per flowerhead (greater than 20), the size of its flowerheads (usually about 1" across or slightly more), and the spreading linear bracts underneath each flowerhead. The leaves are shorter and more narrow than those of many other Aster spp., and they release a pleasant aroma when crushed. In general habit, Aromatic Aster has denser foliage and a bushier habit than other asters, which are usually more tall and lanky. In mass-market horticulture, some plants that are labeled 'Aromatic Aster' appear to be hybrids of Aromatic Aster and Symphyotrichum novae-angliae (New England Aster). These cultivated plants tend to be larger in size and have larger lower leaves; their flowerheads are slightly larger and more double than those of Aromatic Aster.
The compound flowers are daisy-like and about 1–1¼" across. Each compound flower consists of about 20-35 blue-violet or purple ray florets that surround numerous disk florets that are yellow or amber. These disk florets later become reddish purple. Each compound flower is subtended by spreading linear bracts that resemble the upper leaves. The blooming period occurs during the fall and lasts about 1-2 months; a robust plant will be covered with flowerheads. There is no noticeable floral scent, although the crushed foliage and flowerheads have a balsam-like aroma. Aromatic Aster is one of the last wildflowers to bloom prior to heavy frost. The achenes have small tufts of light brown hair and are distributed by the wind. The root system is fibrous and rhizomatous; older plants often have a short caudex. There can be significant variability in the characteristics of plants across different locations.
Cultivation: The preference is full sun and dry conditions, although an average moisture level is tolerated if the site is well-drained. Poor, rocky soil with open terrain is preferred; a high pH is tolerated. Some of the lower leaves may wither away before the plants begin to bloom, but the foliage usually remains quite attractive. At moist fertile sites, this plant has trouble competing against tall aggressive plants, unless such neighbors are selectively weeded out.
Range & Habitat: The native Aromatic Aster occurs primarily in northern Illinois, the hilly sections of southern Illinois, and in areas bordering the Mississippi and Illinois rivers (see Distribution Map). It is generally an uncommon plant, although locally common at a few exceptional sites. Habitats include mesic to dry gravel prairies, dolomite prairies, gravelly hill prairies, limestone glades, and rocky bluffs along major rivers.
Faunal Associations: Many insects visit the flowers, including long-tongued bees, short-tongued bees, small to medium-sized butterflies, and skippers. These insects seek nectar primarily, although the bees also collect pollen. Many kinds of insects feed on the foliage and other parts of asters, including the caterpillars of the butterfly Chlosyne nycteis (Silvery Checkerspot) and many moth species (see Moth Table). The Wild Turkey and possibly other upland gamebirds eat the seeds and foliage to a limited extent. Mammalian herbivores occasionally eat the foliage of asters, even though their food value is low.
Photographic Location: The above photographs were taken in the wildflower garden of the webmaster in Urbana, Illinois.
Comments: This aster has attractive flowers and is fairly easy to cultivate in a sunny rock garden and similar areas. Aromatic Aster can be distinguished from other asters (Symphyotrichum spp.) by the number of ray florets per flowerhead (greater than 20), the size of its flowerheads (usually about 1" across or slightly more), and the spreading linear bracts underneath each flowerhead. The leaves are shorter and more narrow than those of many other Aster spp., and they release a pleasant aroma when crushed. In general habit, Aromatic Aster has denser foliage and a bushier habit than other asters, which are usually more tall and lanky. In mass-market horticulture, some plants that are labeled 'Aromatic Aster' appear to be hybrids of Aromatic Aster and Symphyotrichum novae-angliae (New England Aster). These cultivated plants tend to be larger in size and have larger lower leaves; their flowerheads are slightly larger and more double than those of Aromatic Aster.
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文章
Miss Chen
2018年02月23日
Description: This herbaceous perennial plant is up to 4' tall, consisting of a central stem that branches occasionally near the top. The central stem and side branches are covered with short white hairs. The alternate leaves are up to 4" long and 1" wide, becoming smaller as they ascend the flowering stems. They are lanceolate or oblong, pubescent, and clasp the stem at the base of each leaf. Their margins are smooth, but ciliate.
Clusters of composite flowers occur at the ends of the upper stems. Each composite flower consists of numerous gold or yellow disk florets, which are surrounded by 30 or more ray florets that are purple, lavender, or light pink. Each composite flower is about 1½" across. A mature plant may bear two dozen or more of such flowers, putting forth a showy display. There is no noticeable floral scent. The blooming period occurs from late summer to fall, and lasts about 2 months. The root system consists of a stout caudex with fibrous roots, which often produces short thick rhizomes, enabling this plant to spread vegetatively. The achenes are longitudinally ribbed and slightly hairy, with tufts of hair that enable them to be carried off in the wind.
Cultivation: The preference is full or partial sun, and moist to average conditions. The soil can contain loam or clay. This plant can become stressed out by hot dry weather, often dropping its lower leaves in response, while the remaining leaves may turn yellow or brown. Another problem is that the stems often flop over in the absence of supportive vegetation. Powdery mildew often afflicts the leaves during the cool, moist weather of the fall. This is an easy plant to grow in moist conditions, but it is more difficult to maintain in good condition throughout the year. Sometimes it becomes aggressive and spreads vegetatively.
Range & Habitat: The native New England Aster occurs throughout Illinois, except in a few southern counties (see Distribution Map). It is a common plant. Habitats include moist to mesic black soil prairies, clay prairies, thickets, moist meadows in woodlands, open areas along rivers and lakes, fens, abandoned fields, open areas along railroads and roadsides, and miscellaneous waste areas. Some populations are probably escapes from cultivated plants. This plant colonizes disturbed areas readily, but it also occurs in high quality habitats.
Faunal Associations: The flowers are visited primarily by long-tongued bees, bee flies, butterflies, and skippers. Short-tongued bees and Syrphid flies also visit the flowers, but they collect pollen primarily and are non-pollinating. Among the long-tongued bees, are such visitors as bumblebees, honeybees, Miner bees, and large Leaf-Cutting bees. Cross-pollination by these insects is essential, otherwise the seeds will be infertile. The caterpillars of many moths feed on various parts of this and other asters (see Moth Table). Other insects feeding on this plant include Lygus lineolaris (Tarnished Plant Bug), Poccilocapsus lineatus (Four-Lined Plant Bug), Corythuche marmorata (Chrysanthemum Lace Bug), and Macrosiphum euphoriaca (Potato Aphid). The seeds and leaves of this plant are eatened to a limited extent by the Wild Turkey, while deer, livestock, and rabbits occasionally browse on the foliage, sometimes eating the entire plant. However, New England Aster isn't a preferred food source for these animals.
Photographic Location: The photographs were taken at Judge Webber Park in Urbana, Illinois.
Comments: New England Aster can be variable in terms of its size, color of the flowers, and other characteristics. This plant has attractive flowers with a long blooming period, but it often appears messy by the fall as a result of drought, insects, and disease. It is easy to distinguish this aster from other asters (Symphyotrichum spp.), because its compound flowers are larger in size and they have more numerous ray florets.
Clusters of composite flowers occur at the ends of the upper stems. Each composite flower consists of numerous gold or yellow disk florets, which are surrounded by 30 or more ray florets that are purple, lavender, or light pink. Each composite flower is about 1½" across. A mature plant may bear two dozen or more of such flowers, putting forth a showy display. There is no noticeable floral scent. The blooming period occurs from late summer to fall, and lasts about 2 months. The root system consists of a stout caudex with fibrous roots, which often produces short thick rhizomes, enabling this plant to spread vegetatively. The achenes are longitudinally ribbed and slightly hairy, with tufts of hair that enable them to be carried off in the wind.
Cultivation: The preference is full or partial sun, and moist to average conditions. The soil can contain loam or clay. This plant can become stressed out by hot dry weather, often dropping its lower leaves in response, while the remaining leaves may turn yellow or brown. Another problem is that the stems often flop over in the absence of supportive vegetation. Powdery mildew often afflicts the leaves during the cool, moist weather of the fall. This is an easy plant to grow in moist conditions, but it is more difficult to maintain in good condition throughout the year. Sometimes it becomes aggressive and spreads vegetatively.
Range & Habitat: The native New England Aster occurs throughout Illinois, except in a few southern counties (see Distribution Map). It is a common plant. Habitats include moist to mesic black soil prairies, clay prairies, thickets, moist meadows in woodlands, open areas along rivers and lakes, fens, abandoned fields, open areas along railroads and roadsides, and miscellaneous waste areas. Some populations are probably escapes from cultivated plants. This plant colonizes disturbed areas readily, but it also occurs in high quality habitats.
Faunal Associations: The flowers are visited primarily by long-tongued bees, bee flies, butterflies, and skippers. Short-tongued bees and Syrphid flies also visit the flowers, but they collect pollen primarily and are non-pollinating. Among the long-tongued bees, are such visitors as bumblebees, honeybees, Miner bees, and large Leaf-Cutting bees. Cross-pollination by these insects is essential, otherwise the seeds will be infertile. The caterpillars of many moths feed on various parts of this and other asters (see Moth Table). Other insects feeding on this plant include Lygus lineolaris (Tarnished Plant Bug), Poccilocapsus lineatus (Four-Lined Plant Bug), Corythuche marmorata (Chrysanthemum Lace Bug), and Macrosiphum euphoriaca (Potato Aphid). The seeds and leaves of this plant are eatened to a limited extent by the Wild Turkey, while deer, livestock, and rabbits occasionally browse on the foliage, sometimes eating the entire plant. However, New England Aster isn't a preferred food source for these animals.
Photographic Location: The photographs were taken at Judge Webber Park in Urbana, Illinois.
Comments: New England Aster can be variable in terms of its size, color of the flowers, and other characteristics. This plant has attractive flowers with a long blooming period, but it often appears messy by the fall as a result of drought, insects, and disease. It is easy to distinguish this aster from other asters (Symphyotrichum spp.), because its compound flowers are larger in size and they have more numerous ray florets.
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文章
Miss Chen
2018年02月23日
Description: This perennial herbaceous plant is 1–3½' tall, branching occasionally. The central stem and lateral stems are light green to dull red, terete, and sometimes shallowly grooved; they usually have vertical lines of white hairs. Older lower stems sometimes become brownish, woody-looking, and glabrous. Alternate leaves occur along the entire length of the stems, becoming gradually smaller in size as they ascend. These leaves are up to 5" long and ¾" across; they are narrowly lanceolate, elliptic, or elliptic-rhombic in shape, while their margins are entire (toothless) or sparingly serrated. Usually the lower to middle leaves have a few teeth along their middle to outer margins, while the upper leaves are entire. The leaves taper to acute tips, while their bases are wedge-shaped (cuneate); they are either sessile or taper gradually into short winged petioles. The upper leaf surface is medium to medium-dark green and glabrous, while the lower leaf surface is slightly more pale and usually glabrous (very young leaves may be sparsely short-pubescent below). A reticulated network of secondary veins is clearly visible on the lower side of each leaf, and sometimes it is also visible on the upper side. During cold autumn weather, sometimes the foliage becomes purple. The central stem terminates in a panicle of flowerheads up to 8" long and 4" across; smaller panicles of flowerheads are often produced from upper lateral stems and the axils of upper leaves.
Flowerheads, Leaves, & Leafy Bracts
The branches of these panicles are similar to the stems, except they tend to be more hairy and more grooved. Solitary leafy bracts up to 1½" long and 8 mm. across occur where these branches diverge, and they also occur at the bases of peduncles (basal stalks of the flowerheads). These peduncles are up to 1½" long. Each daisy-like flowerhead spans ½–¾" across, consisting of 20-40 ray florets that surround a dense head of numerous disk florets. The petaloid rays of a flowerhead are white and linear-oblong; when a flowerhead is fully open, they are widely spreading to somewhat declined. The corollas of disk florets 3-5 mm. long, tubular in shape, and 5-lobed along their rims; they are initially yellow, but later become orange-red. The lobes of the corollas are triangular in shape and ascending to widely spreading. The ray florets are fertile and pistillate, while the disk florets are fertile and perfect. Surrounding the base of each flowerhead, there are numerous phyllaries (scale-like floral bracts) in several series that are erect to ascending. The phyllaries are 2-4 mm. long, light to medium green, linear-oblong in shape, and glabrous. The blooming period occurs from late summer into autumn for 1-2 months. Afterwards, the florets are replaced by achenes with small tufts of white hair; they are dispersed by the wind. The achenes are about 1.5–2 mm. long, gray to dark gray, narrowly oblanceoloid in shape, slightly flattened, and finely pubescent. The root system is fibrous and long-rhizomatous. Clonal colonies of plants are often produced from the rhizomes.
Cultivation: The preference is full to partial sun and moist conditions. Favored locations are poorly drained areas that form pools of water temporarily, but later dry out. This plant can tolerate average levels of moisture and some drought, but it won't grow as large and its lower leaves may shrivel away. The soil can contain loam, clay, gravel, or even large rocks – this plant doesn't seem to care. Some foliar disease may occur, such as patches of rust or powdery mildew, but the foliage is usually in good shape during the blooming period of autumn. In damp open areas, this plant may spread aggressively by means of its rhizomes.
Range & Habitat: The native Panicled Aster occurs in most counties of Illinois (see Distribution Map), where it is common. Habitats include disturbed areas of moist prairies, prairie swales, openings and edges of floodplain woodlands, moist meadows along rivers, thickets, gravelly seeps, low areas along ponds and small lakes, edges of marshes, seasonal wetlands, roadside ditches, poorly drained gravelly areas of junkyards, fence rows, pastures, and abandoned fields. This plant often thrives in moist disturbed areas that are subjected to little or no mowing.
Faunal Associations: The nectar and pollen of the flowerheads attract many kinds of insects, including honeybees, bumblebees, leaf-cutting bees (Megachile spp.), Halictid bees (including green metallic bees), Halictid cuckoo bees (Sphecodes spp.), oligolectic Andrenid bees (Andrena spp.), Crabonid wasps (Ectemnius spp. & others), bee wolves (Philanthus spp.), thread-waisted wasps (Ammophila spp.), paper wasps (Polistes spp.), Eumenine wasps, Ichneumonid wasps, Syrphid flies, bee flies (Bombyliidae), Tachinid flies, flesh flies (Helicobia spp. & others), bottle flies (Lucilia spp.), Muscid flies, butterflies (Vanessa spp. & others), skippers, and beetles. Other insects feed destructively on the leaves and other parts of the Panicled Aster (Aster lanceolatus). These species include the leaf beetles Microrhopala xerene, Ophraella pilosa, Paria thoracia, and Sumitrosis inaequalis; larvae of the leaf-mining flies Nemorimyza posticata, Ophiomyia texana, and Phytomyza albiceps; larvae of Asteromyia laeviana (Papery Blister-Gall Midge) and the gall fly Rhopalomyia asteriflorae; the aphid Uroleucon olivei; and caterpillars of a butterfly, Phyciodes tharos (Pearl Crescent); see Clark et al. (2004), Needham et al. (1928), Felt (1917), Blackman & Eastop (2013), and Opler & Krizek (1984). Other insects that feed on this aster and other asters (Symphyotrichum spp.) include the larvae of fruit flies, plant bugs, several aphids, grasshoppers, and the larvae of many moths. Vertebrate animals also use asters as a source of food. The Ruffed Grouse and Wild Turkey feed on the seeds and foliage of these plants, while the Tree Sparrow and White-footed Mouse feed on the seeds only. Mammalian herbivores also browse on the foliage of asters, including deer, rabbits, groundhogs, horses, cattle, and sheep. In particular, White-Tailed Deer are very fond of the foliage of Panicled Aster, browsing its leafy stems to within inches of the ground (Martin et al., 1951/1961; personal observations).
Photographic Location: The photographs were taken at a rock-filled ditch near Urbana, Illinois.
Comments: Panicled Aster (Symphyotrichum lanceolatum) is rather showy when it is in bloom, even though it is often treated as an undesirable weed. This aster can be difficult to distinguish from other asters (Symphyotrichum spp.) that have small flowerheads with white petaloid rays. It has several characteristics that, when they are taken together, are useful in making a correct identification: 1) its flowerheads are usually ½" across or slightly more, 2) its flowerheads have at least 20 ray florets, 3) its leaves have wedged-shaped bases, rather than rounded or cordate (heart-shaped), 4) its mature leaves are hairless on both their upper and lower sides, 5) its stems usually have lines of fine white hairs, and 6) its panicles of flowerheads have conspicuous leafy bracts. Regarding nomenclature, alternative common names for this plant are 'Tall White Aster' and 'White Field Aster,' while older scientific names include Aster lanceolatus, Aster paniculatus and Aster simplex.
Flowerheads, Leaves, & Leafy Bracts
The branches of these panicles are similar to the stems, except they tend to be more hairy and more grooved. Solitary leafy bracts up to 1½" long and 8 mm. across occur where these branches diverge, and they also occur at the bases of peduncles (basal stalks of the flowerheads). These peduncles are up to 1½" long. Each daisy-like flowerhead spans ½–¾" across, consisting of 20-40 ray florets that surround a dense head of numerous disk florets. The petaloid rays of a flowerhead are white and linear-oblong; when a flowerhead is fully open, they are widely spreading to somewhat declined. The corollas of disk florets 3-5 mm. long, tubular in shape, and 5-lobed along their rims; they are initially yellow, but later become orange-red. The lobes of the corollas are triangular in shape and ascending to widely spreading. The ray florets are fertile and pistillate, while the disk florets are fertile and perfect. Surrounding the base of each flowerhead, there are numerous phyllaries (scale-like floral bracts) in several series that are erect to ascending. The phyllaries are 2-4 mm. long, light to medium green, linear-oblong in shape, and glabrous. The blooming period occurs from late summer into autumn for 1-2 months. Afterwards, the florets are replaced by achenes with small tufts of white hair; they are dispersed by the wind. The achenes are about 1.5–2 mm. long, gray to dark gray, narrowly oblanceoloid in shape, slightly flattened, and finely pubescent. The root system is fibrous and long-rhizomatous. Clonal colonies of plants are often produced from the rhizomes.
Cultivation: The preference is full to partial sun and moist conditions. Favored locations are poorly drained areas that form pools of water temporarily, but later dry out. This plant can tolerate average levels of moisture and some drought, but it won't grow as large and its lower leaves may shrivel away. The soil can contain loam, clay, gravel, or even large rocks – this plant doesn't seem to care. Some foliar disease may occur, such as patches of rust or powdery mildew, but the foliage is usually in good shape during the blooming period of autumn. In damp open areas, this plant may spread aggressively by means of its rhizomes.
Range & Habitat: The native Panicled Aster occurs in most counties of Illinois (see Distribution Map), where it is common. Habitats include disturbed areas of moist prairies, prairie swales, openings and edges of floodplain woodlands, moist meadows along rivers, thickets, gravelly seeps, low areas along ponds and small lakes, edges of marshes, seasonal wetlands, roadside ditches, poorly drained gravelly areas of junkyards, fence rows, pastures, and abandoned fields. This plant often thrives in moist disturbed areas that are subjected to little or no mowing.
Faunal Associations: The nectar and pollen of the flowerheads attract many kinds of insects, including honeybees, bumblebees, leaf-cutting bees (Megachile spp.), Halictid bees (including green metallic bees), Halictid cuckoo bees (Sphecodes spp.), oligolectic Andrenid bees (Andrena spp.), Crabonid wasps (Ectemnius spp. & others), bee wolves (Philanthus spp.), thread-waisted wasps (Ammophila spp.), paper wasps (Polistes spp.), Eumenine wasps, Ichneumonid wasps, Syrphid flies, bee flies (Bombyliidae), Tachinid flies, flesh flies (Helicobia spp. & others), bottle flies (Lucilia spp.), Muscid flies, butterflies (Vanessa spp. & others), skippers, and beetles. Other insects feed destructively on the leaves and other parts of the Panicled Aster (Aster lanceolatus). These species include the leaf beetles Microrhopala xerene, Ophraella pilosa, Paria thoracia, and Sumitrosis inaequalis; larvae of the leaf-mining flies Nemorimyza posticata, Ophiomyia texana, and Phytomyza albiceps; larvae of Asteromyia laeviana (Papery Blister-Gall Midge) and the gall fly Rhopalomyia asteriflorae; the aphid Uroleucon olivei; and caterpillars of a butterfly, Phyciodes tharos (Pearl Crescent); see Clark et al. (2004), Needham et al. (1928), Felt (1917), Blackman & Eastop (2013), and Opler & Krizek (1984). Other insects that feed on this aster and other asters (Symphyotrichum spp.) include the larvae of fruit flies, plant bugs, several aphids, grasshoppers, and the larvae of many moths. Vertebrate animals also use asters as a source of food. The Ruffed Grouse and Wild Turkey feed on the seeds and foliage of these plants, while the Tree Sparrow and White-footed Mouse feed on the seeds only. Mammalian herbivores also browse on the foliage of asters, including deer, rabbits, groundhogs, horses, cattle, and sheep. In particular, White-Tailed Deer are very fond of the foliage of Panicled Aster, browsing its leafy stems to within inches of the ground (Martin et al., 1951/1961; personal observations).
Photographic Location: The photographs were taken at a rock-filled ditch near Urbana, Illinois.
Comments: Panicled Aster (Symphyotrichum lanceolatum) is rather showy when it is in bloom, even though it is often treated as an undesirable weed. This aster can be difficult to distinguish from other asters (Symphyotrichum spp.) that have small flowerheads with white petaloid rays. It has several characteristics that, when they are taken together, are useful in making a correct identification: 1) its flowerheads are usually ½" across or slightly more, 2) its flowerheads have at least 20 ray florets, 3) its leaves have wedged-shaped bases, rather than rounded or cordate (heart-shaped), 4) its mature leaves are hairless on both their upper and lower sides, 5) its stems usually have lines of fine white hairs, and 6) its panicles of flowerheads have conspicuous leafy bracts. Regarding nomenclature, alternative common names for this plant are 'Tall White Aster' and 'White Field Aster,' while older scientific names include Aster lanceolatus, Aster paniculatus and Aster simplex.
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