文章
Miss Chen
2018年05月22日
Description: This herbaceous plant is a biennial or short-lived perennial; it is about 1-2' tall, branching occasionally. The stems are glabrous and light green; they are terete or somewhat angular. The alternate leaves are usually trifoliate, although some of the smaller upper leaves are simple. The lower leaves often appear to be palmate with 5 leaflets, but this is because each lateral leaflet has been deeply divided into 2 large lobes. In outline, the lower compound leaves are nearly orbicular in outline (up to 5" wide and 5" across, excluding the petioles) while the upper compound leaves are more narrow. The leaflets and large lobes are obovate, ovate, or broadly elliptic in shape, while their margins are coarsely double-serrated and sometimes cleft along their margins. Leaf venation within each leaflet and lobe is pinnate. The upper leaf surface is yellowish green (in bright sunlight) to dark green (in shade) and glabrous. The lower leaves have long petioles, while those of the upper leaves are much shorter. These petioles are light green, glabrous, and slightly sheathed at their bases; they are grooved above and convex below.
The upper stems terminate in small umbels or compound umbels of greenish white flowers. Each umbel consists of 1-4 umbellets and spans up to 2½" across. Each umbellet has 2-3 pistillate or perfect flowers and about 2-6 staminate flowers (less often, there will be 7-15 staminate flowers); these flowers form a tight cluster that is irregularly globular in shape. The perfect and pistillate flowers are more conspicous because of their bur-like ovaries. These ovaries are about 3-5 mm. in length, globoid-ovoid in shape, and green; their outer surfaces are covered with hooked prickles (about 1 mm. in length). Each flower has 5 greenish white petals and a green calyx with 5 linear-lanceolate lobes; these lobes are shorter than the prickles of the ovaries. The styles of perfect and pistillate flowers (less than 1 mm. in length) are also shorter than the prickles of the ovaries. Each staminate or perfect flower has 5 short stamens.
The blooming period occurs from late spring to mid-summer and lasts about 3 weeks for a colony of plants. There is no noticeable floral scent. Each bur-like fruit contains 2 seeds. The root system is fibrous. This plant spreads by reseeding itself and it occasionally forms colonies.
Cultivation: The preference is light to medium shade, moist to slightly dry conditions, and a loamy soil with an abundance of organic matter.
Range & Habitat: Canadian Black Snakeroot is a common plant that occurs in nearly all counties of Illinois (see Distribution Map), where it is native. Habitats include mesic deciduous woodlands, north-facing bluffs, areas along woodland paths, edges of shaded seeps, fence rows with woody vegetation, edges of yards underneath trees, and flower gardens in shady areas. This plant occurs in both natural habitats of varying quality and disturbed areas.
Faunal Associations: The flowers attract few insect pollinators, although occasionally they are visited by Halictid bees (Lasioglossum spp.), masked bees (Hylaeus spp.), and Syrphid flies, which suck nectar. An aphid, Aphis clydesmithi, sucks plant juices at the stem base and root collar, while another aphid, Aphis saniculae, sucks plant juices from the undersides of the leaves. Canadian Black Snakeroot is the preferred host plant of the latter aphid. The bitter foliage is avoided by grazing livestock and probably other mammalian herbivores as well. The small burry fruits cling readily to the feathers of birds, fur of mammals, and clothing of humans; this helps to distribute the seeds far and wide.
Photographic Location: Underneath a lawn tree in Urbana, Illinois.
Comments: Canadian Black Snakeroot is not very showy, in part because it does not bloom until after the deciduous trees in woodlands have developed their leaves. Except for the bur-like ovaries, the flowers are inconspicuous. This species is well-adapted to the shady conditions that exist underneath trees during the summer, and it can become a minor weed along the edges of yards and in flower gardens. Except for Sanicula gregaria (Clustered Black Snakeroot), which has greenish yellow flowers, the various Sanicula spp. in Illinois have small greenish white flowers. The species of this latter group are rather difficult to distinguish. Canadian Black Snakeroot differs from Sanicula marilandica (Maryland Black Snakeroot) by its short styles, which are no longer than the prickles of its ovaries; the latter species has pairs of curved styles that are much longer than the prickles of its ovaries. Canadian Black Snakeroot differs from Sanicula trifoliata (Large-Fruited Black Snakeroot) by the size and shape of its burry fruits: The fruits of the former species are 3-5 mm. long and ovoid-globoid in shape, while the fruits of the latter species are at least 5.5 mm. in length and ovoid in shape. Furthermore, the calyx lobes of the latter species are as long or longer than the surrounding prickles, and its stamens are longer and more conspicuous than those Canadian Black Snakeroot.
The upper stems terminate in small umbels or compound umbels of greenish white flowers. Each umbel consists of 1-4 umbellets and spans up to 2½" across. Each umbellet has 2-3 pistillate or perfect flowers and about 2-6 staminate flowers (less often, there will be 7-15 staminate flowers); these flowers form a tight cluster that is irregularly globular in shape. The perfect and pistillate flowers are more conspicous because of their bur-like ovaries. These ovaries are about 3-5 mm. in length, globoid-ovoid in shape, and green; their outer surfaces are covered with hooked prickles (about 1 mm. in length). Each flower has 5 greenish white petals and a green calyx with 5 linear-lanceolate lobes; these lobes are shorter than the prickles of the ovaries. The styles of perfect and pistillate flowers (less than 1 mm. in length) are also shorter than the prickles of the ovaries. Each staminate or perfect flower has 5 short stamens.
The blooming period occurs from late spring to mid-summer and lasts about 3 weeks for a colony of plants. There is no noticeable floral scent. Each bur-like fruit contains 2 seeds. The root system is fibrous. This plant spreads by reseeding itself and it occasionally forms colonies.
Cultivation: The preference is light to medium shade, moist to slightly dry conditions, and a loamy soil with an abundance of organic matter.
Range & Habitat: Canadian Black Snakeroot is a common plant that occurs in nearly all counties of Illinois (see Distribution Map), where it is native. Habitats include mesic deciduous woodlands, north-facing bluffs, areas along woodland paths, edges of shaded seeps, fence rows with woody vegetation, edges of yards underneath trees, and flower gardens in shady areas. This plant occurs in both natural habitats of varying quality and disturbed areas.
Faunal Associations: The flowers attract few insect pollinators, although occasionally they are visited by Halictid bees (Lasioglossum spp.), masked bees (Hylaeus spp.), and Syrphid flies, which suck nectar. An aphid, Aphis clydesmithi, sucks plant juices at the stem base and root collar, while another aphid, Aphis saniculae, sucks plant juices from the undersides of the leaves. Canadian Black Snakeroot is the preferred host plant of the latter aphid. The bitter foliage is avoided by grazing livestock and probably other mammalian herbivores as well. The small burry fruits cling readily to the feathers of birds, fur of mammals, and clothing of humans; this helps to distribute the seeds far and wide.
Photographic Location: Underneath a lawn tree in Urbana, Illinois.
Comments: Canadian Black Snakeroot is not very showy, in part because it does not bloom until after the deciduous trees in woodlands have developed their leaves. Except for the bur-like ovaries, the flowers are inconspicuous. This species is well-adapted to the shady conditions that exist underneath trees during the summer, and it can become a minor weed along the edges of yards and in flower gardens. Except for Sanicula gregaria (Clustered Black Snakeroot), which has greenish yellow flowers, the various Sanicula spp. in Illinois have small greenish white flowers. The species of this latter group are rather difficult to distinguish. Canadian Black Snakeroot differs from Sanicula marilandica (Maryland Black Snakeroot) by its short styles, which are no longer than the prickles of its ovaries; the latter species has pairs of curved styles that are much longer than the prickles of its ovaries. Canadian Black Snakeroot differs from Sanicula trifoliata (Large-Fruited Black Snakeroot) by the size and shape of its burry fruits: The fruits of the former species are 3-5 mm. long and ovoid-globoid in shape, while the fruits of the latter species are at least 5.5 mm. in length and ovoid in shape. Furthermore, the calyx lobes of the latter species are as long or longer than the surrounding prickles, and its stamens are longer and more conspicuous than those Canadian Black Snakeroot.
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文章
Miss Chen
2018年05月21日
Description: This herbaceous perennial plant is ½–1½' tall, branching occasionally. The leafy stems have a tendency to lean to one side or sprawl across the ground. The stems are light green to reddish green, glabrous to hairy, and often somewhat angular. The alternate compound leaves are simple odd-pinnate and up to 8" long, consisting of about 5-15 leaflets. The petioles and rachises of these compound leaves are light green to reddish green and glabrous to hairy; they are grooved above and convex below. The leaflets are ¾-1¼" long and about one-third as much across; they are elliptic to broadly elliptic-oblong, smooth (entire) along their margins, medium green, glabrous (or nearly so), and sessile (or nearly so). The upper stems terminate in rather loose panicles of floppy or nodding flowers spanning 1½-3" across. Some panicles are also produced from the axils of upper leaves on long peduncles up to 6" long. The pedicels are up to 1" long.
Both the peduncles and pedicels of these panicles are light green to reddish green and glabrous to hairy. The campanulate (bell-shaped) flowers are up to 16 mm. (2/3") across. Each flower has 5 rounded petals that are light blue-violet, a short-tubular calyx with 5 triangular teeth, 5 stamens with white anthers, and a pistil with a slender white style that become tripartite toward its tip. The calyx is light green to reddish purple and glabrous to hairy. There are fine veins that run along the length of the petals. The stamens are the same length as, or shorter than, the petals of the flowers. The blooming period usually occurs during the late spring, lasting about 2-3 weeks. Afterwards, the flowers are replaced by 3-celled seed capsules; these capsules are about 6 mm. (¼") in length and ovoid in shape; they are few-seeded. The root system consists of a short vertical crown with abundant fibrous roots. This plant spreads by reseeding itself.
Cultivation: The preference is light shade or dappled sun, more or less mesic conditions, and loamy soil with decaying organic matter. This plant is not aggressive; it is able to adapt to somewhat shady gardens that are located near deciduous trees.
Range & Habitat: The native Jacob's Ladder is an occasional to locally common plant that occurs in most areas of Illinois, except for some counties in the central portion of the state (see Distribution Map). Habitats include deciduous woodlands, lower wooded slopes, bases of bluffs, shaded banks of streams and rivers, bottoms of sandstone canyons, and areas along woodland paths. Jacob's Ladder is found in higher quality natural habitats that are dominated by various deciduous trees.
Faunal Associations: The nectar and pollen of the flowers attract bees primarily, including honeybees, bumblebees, little carpenter bees (Ceratina spp.), mason bees (Osmia spp.), cuckoo bees (Nomada spp.), Halictid bees (Augochlorella spp., Lasioglossum spp.), and Andrenid bees (Andrena spp.). A species from this last group, Andrena polemonii, is a specialist pollinator (oligolege) of Polemonium spp. (Jacob's Ladder, Greek Valerian). The flowers are also visited by Bombylius major (Giant Bee Fly), butterflies, skippers, and moths, which seek nectar. The larvae of two moths, Coleophora polemoniella and Scrobipalpula polemoniella, mine the leaflets. An aphid, Nasonovia hottesi, sucks the sap of these plants.
Photographic Location: A flower garden at Crystal Lake Park in Urbana, Illinois.
Comments: This is a rather floppy plant, although both the flowers and foliage are quite attractive. The bell-shaped flowers and compound leaves together provide Jacob's Ladder with a distinctive appearance. The only other species that resembles it, Polemonium vanbruntiae (Greek Valerian), which is native to some of the Eastern States, doesn't occur in the wild in Illinois. This latter species is more erect in habit, and it has slightly larger flowers with exerted stamens. The flowers of this latter species are usually a darker shade of blue than those of Jacob's Ladder. The common name of Polemonium reptans refers to the pairs of opposite leaflets on the compound leaves, which supposedly resemble a series of steps on a ladder in a dream by the biblical Jacob.
Both the peduncles and pedicels of these panicles are light green to reddish green and glabrous to hairy. The campanulate (bell-shaped) flowers are up to 16 mm. (2/3") across. Each flower has 5 rounded petals that are light blue-violet, a short-tubular calyx with 5 triangular teeth, 5 stamens with white anthers, and a pistil with a slender white style that become tripartite toward its tip. The calyx is light green to reddish purple and glabrous to hairy. There are fine veins that run along the length of the petals. The stamens are the same length as, or shorter than, the petals of the flowers. The blooming period usually occurs during the late spring, lasting about 2-3 weeks. Afterwards, the flowers are replaced by 3-celled seed capsules; these capsules are about 6 mm. (¼") in length and ovoid in shape; they are few-seeded. The root system consists of a short vertical crown with abundant fibrous roots. This plant spreads by reseeding itself.
Cultivation: The preference is light shade or dappled sun, more or less mesic conditions, and loamy soil with decaying organic matter. This plant is not aggressive; it is able to adapt to somewhat shady gardens that are located near deciduous trees.
Range & Habitat: The native Jacob's Ladder is an occasional to locally common plant that occurs in most areas of Illinois, except for some counties in the central portion of the state (see Distribution Map). Habitats include deciduous woodlands, lower wooded slopes, bases of bluffs, shaded banks of streams and rivers, bottoms of sandstone canyons, and areas along woodland paths. Jacob's Ladder is found in higher quality natural habitats that are dominated by various deciduous trees.
Faunal Associations: The nectar and pollen of the flowers attract bees primarily, including honeybees, bumblebees, little carpenter bees (Ceratina spp.), mason bees (Osmia spp.), cuckoo bees (Nomada spp.), Halictid bees (Augochlorella spp., Lasioglossum spp.), and Andrenid bees (Andrena spp.). A species from this last group, Andrena polemonii, is a specialist pollinator (oligolege) of Polemonium spp. (Jacob's Ladder, Greek Valerian). The flowers are also visited by Bombylius major (Giant Bee Fly), butterflies, skippers, and moths, which seek nectar. The larvae of two moths, Coleophora polemoniella and Scrobipalpula polemoniella, mine the leaflets. An aphid, Nasonovia hottesi, sucks the sap of these plants.
Photographic Location: A flower garden at Crystal Lake Park in Urbana, Illinois.
Comments: This is a rather floppy plant, although both the flowers and foliage are quite attractive. The bell-shaped flowers and compound leaves together provide Jacob's Ladder with a distinctive appearance. The only other species that resembles it, Polemonium vanbruntiae (Greek Valerian), which is native to some of the Eastern States, doesn't occur in the wild in Illinois. This latter species is more erect in habit, and it has slightly larger flowers with exerted stamens. The flowers of this latter species are usually a darker shade of blue than those of Jacob's Ladder. The common name of Polemonium reptans refers to the pairs of opposite leaflets on the compound leaves, which supposedly resemble a series of steps on a ladder in a dream by the biblical Jacob.
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文章
Miss Chen
2018年05月21日
Description: This herbaceous perennial plant is 1–1½' tall. Infertile plants are unbranched, producing a single leaf from a long stalk, while fertile plants produce a pair of leaves on long petioles at the apex of this stalk. The stalks are light green to pale reddish green, glabrous, and terete (circular in circumference). The leaves of infertile plants are up to 1' long and 1' across; they are orbicular in outline, fully peltate, and deeply divided in 6-9 palmate lobes. The leaves of fertile plants are similar, although they are less orbicular in outline, only marginally peltate, and they tend to have fewer lobes (typically 5-6). The leaves of both infertile and fertile plants have lobes that are obovate in shape. The outer margins of these lobes are coarsely dentate and often shallowly cleft; less typically, they are coarsely crenate, slightly undulate, or smooth (entire). The upper leaf surface is medium to dark green and glabrous. On fertile plants, the ascending petioles of the leaves are 3-6" long, light green to pale reddish green, glabrous, and terete. The petioles join the leaf blades toward the inner margins of the latter. Each fertile plant produces a single nodding flower where the 2 petioles branch from each other.
This flower is about 1½" across, consisting of 6-9 white petals, 6 light green sepals, 12-18 stamens, and a superior ovary with a dome-shaped cluster of stigmata at its apex. Both the petals and sepals are oval-obovate in shape; the latter are glabrous and early-deciduous. The ovary is ovoid in shape and light green to pale yellow. The stamens have white filaments and yellow anthers. The pedicel of the flower is about 1½" long, light green to yellowish green, and glabrous. The blooming period occurs from mid- to late spring, lasting about 2-3 weeks. Individual flowers are short-lived; they have a pleasant fragrance. Each flower is replaced by an ovoid berry that is fleshy and contains several seeds. At maturity, this berry is about 1½" long and pale yellow. A berry is produced only when cross-pollination of the flower occurs. The root system is long-rhizomatous and fibrous. Mayapple often produces dense colonial colonies that exclude other spring-flowering plants.
Cultivation: The preference is dappled sunlight to light shade, moist to slightly dry conditions, and a rich loamy soil with abundant organic matter. This plant is easy to start from rhizomes and it will readily adapt to garden areas near deciduous trees. It is a strong colonizer and may spread aggressively in some situations. Young foliage is vulnerable to late-frost damage. The mature foliage dies down by the end of summer.
Range & Habitat: The native Mayapple is a common plant that occurs in every county of Illinois (see Distribution Map). It is found primarily in mesic deciduous woodlands, open woodlands, small woodland openings, savannas, and edges of hillside seeps in wooded areas. Mayapple occurs in high quality old-growth woodlands and also open woodlands that have some history of disturbance.
Faunal Associations: The flowers are cross-pollinated by bumblebees and other long-tongued bees. These insects collect pollen and possibly suck nectar. The larvae of a sawfly, Aglaostigma quattuordecimpunctatum, feed on the leaves of Mayapple (Smith, 2006). Adults of a thrips, Ctenothrips bridwelli, have been found on the foliage (Stannard, 1968). The foliage of Mayapple is avoided by mammalian herbivores because of its poisonous qualities and bitter taste. The seeds and rhizomes are also poisonous. The berries are edible if they are fully ripe; they are eaten by box turtles and possibly by such mammals as opossums, raccoons, and skunks. The seeds are distributed to new locations in the feces of these animals.
Photographic Location: A mesic deciduous woodland at Busey Woods in Urbana, Illinois.
Comments: Mayapple is a familiar woodland plant with interesting foliage. The flowers are large and attractive, but they are sparingly produced and mostly hidden by the large leaves. Mayapple develops very quickly during the warmer days of spring. There is no other plant within the state that resembles it; the only other species in this genus occurs in Asia. People can eat the ripe berries in limited amounts, even though they may be mildly toxic. The flavor is bland and resembles an overripe melon.
This flower is about 1½" across, consisting of 6-9 white petals, 6 light green sepals, 12-18 stamens, and a superior ovary with a dome-shaped cluster of stigmata at its apex. Both the petals and sepals are oval-obovate in shape; the latter are glabrous and early-deciduous. The ovary is ovoid in shape and light green to pale yellow. The stamens have white filaments and yellow anthers. The pedicel of the flower is about 1½" long, light green to yellowish green, and glabrous. The blooming period occurs from mid- to late spring, lasting about 2-3 weeks. Individual flowers are short-lived; they have a pleasant fragrance. Each flower is replaced by an ovoid berry that is fleshy and contains several seeds. At maturity, this berry is about 1½" long and pale yellow. A berry is produced only when cross-pollination of the flower occurs. The root system is long-rhizomatous and fibrous. Mayapple often produces dense colonial colonies that exclude other spring-flowering plants.
Cultivation: The preference is dappled sunlight to light shade, moist to slightly dry conditions, and a rich loamy soil with abundant organic matter. This plant is easy to start from rhizomes and it will readily adapt to garden areas near deciduous trees. It is a strong colonizer and may spread aggressively in some situations. Young foliage is vulnerable to late-frost damage. The mature foliage dies down by the end of summer.
Range & Habitat: The native Mayapple is a common plant that occurs in every county of Illinois (see Distribution Map). It is found primarily in mesic deciduous woodlands, open woodlands, small woodland openings, savannas, and edges of hillside seeps in wooded areas. Mayapple occurs in high quality old-growth woodlands and also open woodlands that have some history of disturbance.
Faunal Associations: The flowers are cross-pollinated by bumblebees and other long-tongued bees. These insects collect pollen and possibly suck nectar. The larvae of a sawfly, Aglaostigma quattuordecimpunctatum, feed on the leaves of Mayapple (Smith, 2006). Adults of a thrips, Ctenothrips bridwelli, have been found on the foliage (Stannard, 1968). The foliage of Mayapple is avoided by mammalian herbivores because of its poisonous qualities and bitter taste. The seeds and rhizomes are also poisonous. The berries are edible if they are fully ripe; they are eaten by box turtles and possibly by such mammals as opossums, raccoons, and skunks. The seeds are distributed to new locations in the feces of these animals.
Photographic Location: A mesic deciduous woodland at Busey Woods in Urbana, Illinois.
Comments: Mayapple is a familiar woodland plant with interesting foliage. The flowers are large and attractive, but they are sparingly produced and mostly hidden by the large leaves. Mayapple develops very quickly during the warmer days of spring. There is no other plant within the state that resembles it; the only other species in this genus occurs in Asia. People can eat the ripe berries in limited amounts, even though they may be mildly toxic. The flavor is bland and resembles an overripe melon.
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Miss Chen
2018年05月21日
Description: This annual plant is ½–2' tall, branching occasionally in the upper half. The stems are smooth, terete, glabrous, and translucent. They are light green, greyish green, or reddish green in appearance; some of the larger stems may be slightly ribbed. The opposite leaves are ¾–4" long and about one-half as much across. They are ovate, hairless, and coarsely serrated. Each leaf has a thin membranous texture with a prominent central vein and two conspicuous side veins. The upper surface is green or dark green, while the lower surface is light green or nearly white. The petioles of the leaves are quite long, frequently 1" in length or more.
From the axil of each upper leaf, there develops a narrow raceme of flowers up to 1" long. This raceme is usually shorter than the petiole, slightly curved, and more or less horizontal. Each plant has separate male and/or female flowers that are less than 1/8" (3 mm.) long, and they are either greenish white or greenish yellow. The male flowers have no petals, 4 sepals, and 4 stamens, while the female flowers have no petals, 3 sepals, and 1 pistil. Toward the inner surface of the sepals are small scales. The blooming period occurs from mid-summer to early fall, lasting about 1 month. There is no floral scent. Cross-pollination of the flowers is by wind. The tiny achenes are green, sometimes with black stripes. They can be blown about by the wind, and in this manner spread to new areas.
Cultivation: The preference is light shade, moist to wet conditions, and rich loamy soil. The foliage is little bothered by disease and is it is usually quite attractive. Standing water is tolerated if it is temporary.
Range & Habitat: The native Clearweed is a common woodland plant that occurs in almost all counties of Illinois (see Distribution Map). Habitats include poorly drained areas of upland forests, floodplain forests, crevices in rocky canyons, and shady or partially shaded wetland areas, including seeps, borders of small streams, and low areas along vernal pools. The moist wooded areas where this plant occurs are typically dominated by such deciduous trees as Silver Maple, Sugar Maple, American Sycamore, River Birch, Green Ash, etc. Clearweed often forms large colonies by reseeding itself.
Faunal Associations: The flowers are wind-pollinated, therefore they don't attract many insects. The caterpillars of the following butterflies feed on the foliage of Clearweed: Nymphalis milberti (Milbert's Tortoiseshell), Polygonia comma (Comma), Polygonia interrogationis (Question Mark), and Vanessa atalanta (Red Admiral). These caterpillars feed on other members of the Nettle family as well. The larvae of a moth, Cosmopterix pulcherimella (Beautiful Cosmopterix Moth), mine the leaves. An aphid, Pseudasiphonaphis corni, uses Clearweed as a summer host, where they suck juices from the stems and flowering stalks. This species is also one of the host plants of a polyphagous leafhopper, Empoasca recurvata.
Photographic Location: The plants were growing in a shady area along a small stream at Meadowbrook Park in Urbana, Illinois.
Comments: The most unusual characteristic of this plant is the translucency of the foliage – this has been useful in biology classes to show the uptake of liquids from the roots into the stems and leaves. A less common species of Clearweed, Pilea fontana, has stems that are less translucent and its achenes are black, rather than green. Clearweed resembles other members of the Nettle family as well, but it lacks the stinging hairs that can be found on Urtica dioica (Stinging Nettle) and Laportea canadensis (Wood Nettle). While Boehmeria cylindrica (False Nettle) lacks stinging hairs, its stems aren't translucent and its racemes of flowers are more erect and longer than Clearweed's racemes.
From the axil of each upper leaf, there develops a narrow raceme of flowers up to 1" long. This raceme is usually shorter than the petiole, slightly curved, and more or less horizontal. Each plant has separate male and/or female flowers that are less than 1/8" (3 mm.) long, and they are either greenish white or greenish yellow. The male flowers have no petals, 4 sepals, and 4 stamens, while the female flowers have no petals, 3 sepals, and 1 pistil. Toward the inner surface of the sepals are small scales. The blooming period occurs from mid-summer to early fall, lasting about 1 month. There is no floral scent. Cross-pollination of the flowers is by wind. The tiny achenes are green, sometimes with black stripes. They can be blown about by the wind, and in this manner spread to new areas.
Cultivation: The preference is light shade, moist to wet conditions, and rich loamy soil. The foliage is little bothered by disease and is it is usually quite attractive. Standing water is tolerated if it is temporary.
Range & Habitat: The native Clearweed is a common woodland plant that occurs in almost all counties of Illinois (see Distribution Map). Habitats include poorly drained areas of upland forests, floodplain forests, crevices in rocky canyons, and shady or partially shaded wetland areas, including seeps, borders of small streams, and low areas along vernal pools. The moist wooded areas where this plant occurs are typically dominated by such deciduous trees as Silver Maple, Sugar Maple, American Sycamore, River Birch, Green Ash, etc. Clearweed often forms large colonies by reseeding itself.
Faunal Associations: The flowers are wind-pollinated, therefore they don't attract many insects. The caterpillars of the following butterflies feed on the foliage of Clearweed: Nymphalis milberti (Milbert's Tortoiseshell), Polygonia comma (Comma), Polygonia interrogationis (Question Mark), and Vanessa atalanta (Red Admiral). These caterpillars feed on other members of the Nettle family as well. The larvae of a moth, Cosmopterix pulcherimella (Beautiful Cosmopterix Moth), mine the leaves. An aphid, Pseudasiphonaphis corni, uses Clearweed as a summer host, where they suck juices from the stems and flowering stalks. This species is also one of the host plants of a polyphagous leafhopper, Empoasca recurvata.
Photographic Location: The plants were growing in a shady area along a small stream at Meadowbrook Park in Urbana, Illinois.
Comments: The most unusual characteristic of this plant is the translucency of the foliage – this has been useful in biology classes to show the uptake of liquids from the roots into the stems and leaves. A less common species of Clearweed, Pilea fontana, has stems that are less translucent and its achenes are black, rather than green. Clearweed resembles other members of the Nettle family as well, but it lacks the stinging hairs that can be found on Urtica dioica (Stinging Nettle) and Laportea canadensis (Wood Nettle). While Boehmeria cylindrica (False Nettle) lacks stinging hairs, its stems aren't translucent and its racemes of flowers are more erect and longer than Clearweed's racemes.
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Miss Chen
2018年05月21日
Description: This herbaceous perennial plant is about 1½–3' tall. It is more or less erect and either sparingly branched or unbranched. The stems are light green to dark purple, angular-terete, and slightly pubescent. Pairs of opposite leaves occur along each stem. The leaf blades are up to 5" long and 2½" across; they are dull green, hairless, ovate in shape, and crenate-dentate along their margins. The lower leaves have slender petioles up to one-half the length of their blades, while the upper leaves have much shorter petioles.
The upper stems terminate in slender spike-like racemes of flowers up to 1' long. In addition, secondary racemes are often produced from the uppermost pairs of leaves. The flowers are arranged in opposite pairs along the upper one-half or upper one-third of each raceme. The central stalk of the raceme is usually dark purple. Each flower is up to 1/3" (8 mm.) in length; it consists of a tubular-ovoid calyx and a slender corolla that is pale purplish white and divides into two lips. The small upper lip has a rounded edge, which is slightly indented in the middle; the long lower lip divides into 3 lobes, functioning as a landing pad for visiting insects. Within the corolla, there is a single style and 4 stamens. The small calyx is light green and hairless; it has 3 teeth that are long, slender, and purple along its upper/outer side, while the opposite side of the calyx has a pair of much smaller teeth. The pedicels of the flowers are very short; at the base of each pedicel, there is a pair of tiny bracts (bracteoles). While individual flowers are blooming, they are held horizontally; shortly afterwards, their corollas fall away and their calyces bend downward to become appressed against the stalk of their racemes. The blooming period occurs during the summer and lasts 1-2 months. Only a few flowers are in bloom at the same time. Each flower produces a single seed that develops within the calyx. This plant reproduces by reseeding itself.
Cultivation: Lopseed prefers a sheltered location that provides light to medium shade, moist to mesic conditions, and a rich woodland soil with abundant organic matter.
Range & Habitat: The native Lopseed has been found in most counties of Illinois, however it is only occasionally encountered and its populations are scattered (Distribution Map). Habitats include rich deciduous woodlands in moist to mesic conditions. Lopseed is largely restricted to higher quality woodlands where the original ground flora is still intact. While it is little known, Lopseed has a wide distribution in North America and east-central Asia.
Faunal Associations: Small bees occasionally visit the flowers for nectar. Robertson (1928) observed only two bees, Ceratina dupla and Augochlorella striata, as floral visitors of Lopseed. The former species is a Little Carpenter bee, while the latter species is a Green Metallic bee. Other records of floral-faunal relationships are sparse. A polyphagous insect, Proxys punctulatus (Black Stink Bug), sucks juices from the foliage of Lopseed (and many other plants). White-Tailed Deer reportedly dislike this plant as a food source and don't graze on the foliage.
Photographic Location: Spitzler Woods in Macon County, Illinois. The photographs were taken during the autumn when the flowers were no longer in bloom.
Comments: This woodland plant is often overlooked because it lacks showy flowers. As a general rule, shade-loving woodland plants that bloom during the summer have small light-colored flowers because they have access to very limited amounts of energy from low levels of sunlight. Plants that grow in open woodlands or prairies have access to more sunlight and usually produce larger flowers. Woodland wildflowers that bloom in the spring can also produce large showy flowers, largely because the canopy trees haven't fully developed their leaves, and thus more sunlight reaches the ground vegetation. Lopseed is an unusual plant that has been assigned to its own plant family. It resembles members of the Mint family (Lamiaceae) in many ways, but each of its flowers produces only a single seed. In contrast, individual flowers of plants in the Mint family typically produce either 2 or 4 seeds.
The upper stems terminate in slender spike-like racemes of flowers up to 1' long. In addition, secondary racemes are often produced from the uppermost pairs of leaves. The flowers are arranged in opposite pairs along the upper one-half or upper one-third of each raceme. The central stalk of the raceme is usually dark purple. Each flower is up to 1/3" (8 mm.) in length; it consists of a tubular-ovoid calyx and a slender corolla that is pale purplish white and divides into two lips. The small upper lip has a rounded edge, which is slightly indented in the middle; the long lower lip divides into 3 lobes, functioning as a landing pad for visiting insects. Within the corolla, there is a single style and 4 stamens. The small calyx is light green and hairless; it has 3 teeth that are long, slender, and purple along its upper/outer side, while the opposite side of the calyx has a pair of much smaller teeth. The pedicels of the flowers are very short; at the base of each pedicel, there is a pair of tiny bracts (bracteoles). While individual flowers are blooming, they are held horizontally; shortly afterwards, their corollas fall away and their calyces bend downward to become appressed against the stalk of their racemes. The blooming period occurs during the summer and lasts 1-2 months. Only a few flowers are in bloom at the same time. Each flower produces a single seed that develops within the calyx. This plant reproduces by reseeding itself.
Cultivation: Lopseed prefers a sheltered location that provides light to medium shade, moist to mesic conditions, and a rich woodland soil with abundant organic matter.
Range & Habitat: The native Lopseed has been found in most counties of Illinois, however it is only occasionally encountered and its populations are scattered (Distribution Map). Habitats include rich deciduous woodlands in moist to mesic conditions. Lopseed is largely restricted to higher quality woodlands where the original ground flora is still intact. While it is little known, Lopseed has a wide distribution in North America and east-central Asia.
Faunal Associations: Small bees occasionally visit the flowers for nectar. Robertson (1928) observed only two bees, Ceratina dupla and Augochlorella striata, as floral visitors of Lopseed. The former species is a Little Carpenter bee, while the latter species is a Green Metallic bee. Other records of floral-faunal relationships are sparse. A polyphagous insect, Proxys punctulatus (Black Stink Bug), sucks juices from the foliage of Lopseed (and many other plants). White-Tailed Deer reportedly dislike this plant as a food source and don't graze on the foliage.
Photographic Location: Spitzler Woods in Macon County, Illinois. The photographs were taken during the autumn when the flowers were no longer in bloom.
Comments: This woodland plant is often overlooked because it lacks showy flowers. As a general rule, shade-loving woodland plants that bloom during the summer have small light-colored flowers because they have access to very limited amounts of energy from low levels of sunlight. Plants that grow in open woodlands or prairies have access to more sunlight and usually produce larger flowers. Woodland wildflowers that bloom in the spring can also produce large showy flowers, largely because the canopy trees haven't fully developed their leaves, and thus more sunlight reaches the ground vegetation. Lopseed is an unusual plant that has been assigned to its own plant family. It resembles members of the Mint family (Lamiaceae) in many ways, but each of its flowers produces only a single seed. In contrast, individual flowers of plants in the Mint family typically produce either 2 or 4 seeds.
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