Stems第36页 - 绿手指 - 养花技巧、花生病了怎么办、花园打理和设计

Description: This perennial wildflower is 1½–3' tall, producing one or more unbranched stems at the base that are erect to ascending. The stems are light green to reddish green and glabrous to densely pubescent. Along each stem, there are numerous alternate leaves that are ascending to widely spreading. Individual leaves are 2-6" long and 1/8-1/2" (3-12 mm.) across; they are linear to linear-lanceolate and smooth along their margins. Their upper surfaces are medium green and glabrous. The leaves often curve upward along their central veins. The petioles of the leaves are about ¼" long and light green. Globoid umbels of greenish white flowers about 1½-2" across develop from the axils of the middle to upper leaves (one umbel per leaf). Each umbel has 30-100 flowers on pedicels about ½-¾" long. The slender pedicels are light green and pubescent. Individual flowers are about 1/8" (3 mm.) across and 1/4" (6 mm.) long. Each flower has 5 sepals, a corolla with 5 narrow lobes, 5 upright hoods without horns, and a short central column containing the reproductive organs. The lobes of the corolla hang downward from the face of the flower (pointing toward the center of the umbel). The lobes are mostly greenish white, although they become purplish toward their tips. The peduncles of the umbels are about 1-1½" long, light green, and pubescent. The blooming period occurs from mid- to late summer and lasts about 2 months. Fertile flowers develop into follicles (seedpods that split open along one side) about 4-5" long and up to ½" across that are narrowly lanceoloid in shape. The surface of each follicle is canescent and smooth. Each follicle contain numerous seeds with tufts of white hair that are released to the wind at maturity. The root system consists of a taproot. This wildflower spreads by reseeding itself.

Cultivation: The preference is full sun, moist to dry conditions, and sandy or gravelly soil. Soil containing loam or clay-loam is also tolerated.

Range & Habitat: Tall Green Milkweed is occasional throughout Illinois. It is a native herbaceous plant. Habitats include dry-mesic railroad prairies, sand prairies, rocky glades, edges of sandy wetlands, roadsides, pastures, and abandoned fields. This milkweed can be found in both high quality habitats and disturbed areas that are sunny.

Faunal Associations: The flowers of Tall Green Milkweed are cross-pollinated primarily by long-tongued bees and wasps. Bee visitors include honeybees, bumblebees, and leaf-cutting bees (Megachile spp.). To a lesser extent, the flowers also attract small butterflies and day-flying moths (e.g., Cisseps fulvicollis). These insects obtain nectar from the flowers. Milkweeds attract a special group of insects that are oligophagous on various parts of these plants. These insect feeders include caterpillars of the butterfly Danaus plexippus (Monarch) and caterpillars of the moths Cycnia inopinatus (Unexpected Cycnia), Cycnia tenera (Delicate Cycnia), and Euchaetes egle (Milkweed Tiger Moth). Some of these moths seem to prefer some Asclepias spp. over others. The larvae of some long-horned beetles bore through the stems and roots of milkweeds, specifically: Tetraopes tetrophthalmus (Red Milkweed Beetle), Tetraopes femoratus (Large Red Milkweed Beetle), and Tetraopes quinquemaculatus. This last species has been found on Tall Green Milkweed. When the follicles of milkweeds are present, the seeds are eaten by Lygaeus kalmii (Small Milkweed Bug) and Oncopeltus fasciatus (Large Milkweed Bug). Occasionally, aphids are found on the upper stems and leaf undersides; these species include Aphis asclepiadis, Myzocallis asclepiadis, Myzocallis punctatus, and Aphis nerii (Introduced Milkweed Aphid). Because the milky latex of the leaves and stems contain cardiac glycosides and possess a bitter flavor, they are usually avoided by mammalian herbivores. The White-Footed Mouse eats the seeds of milkweeds to a minor extent, while the Eastern Goldfinch uses the silky hairs of the seeds in the construction of its nests.

Photographic Location: A prairie in Fayette County, Illinois. The photograph of the flowering plant was taken by Keith & Patty Horn (Copyright © 2009). A caterpillar of the Monarch butterfly is conspicuous in this photo.

Comments: Tall Green Milkweed is one of the lesser known species of milkweed that is occasionally found in upland prairies. It is distinguished primarily by its greenish white umbels of flowers, lack of horns in the hoods of the flowers, and narrow alternate leaves. It also produces more umbels of flowers per plant than most milkweeds. Other milkweeds usually have opposite leaves. A somewhat similar species, Asclepias viridiflora (Short Green Milkweed), is a shorter plant with pairs of opposite leaves. It produces only 1-2 umbels of flowers that nod downward. Another similar species, Asclepias verticillata (Whorled Milkweed), is a smaller plant with whorls of grass-like leaves; these leaves are more narrow (filiform-linear) than those of Tall Green Milkweed.

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Description: This perennial plant becomes about 2-3' tall when it is mature, branching occasionally in the upper half. The stems are covered in a dense mat of short white hairs. The alternate leaves are up to 3½" long and 1" across. They are usually oblanceolate, narrowly ovate, or linear. The lower leaves may have a few lobes or coarse teeth towards their tips, while the upper leaves have smooth margins. Like the stems, the leaves have a dense mat of short white hairs, especially on the lower surface. This variety of White Sage has dense white hairs on the upper surface of the leaves as well, except for the oldest leaves toward the bottom of the plant. The leaves are sessile against the stem, or have short petioles. Some of the upper stems terminate in elongated spikes or narrow racemes of compound flowers. Each flowerhead is only 1/8" (3 mm.) across, and contains numerous whitish green disk florets that are inconspicuous. The blooming period is late summer to early fall, and lasts about 2-3 weeks. There is no floral scent, although the foliage of this plant is quite aromatic. Pollination is by wind, rather than insects. The tiny seeds are without tufts of hair, but are small enough to be distributed by the wind. The root system is rhizomatous, and can form a dense mat of roots near the surface of the ground. As a result, this plant has a strong tendency to form clonal colonies that exclude other plants.

Cultivation: The preference is full sun and dry conditions. Poor soil containing hardpan clay, rocky material, or sand is actually preferred as a medium for growth, as this reduces competition from other plants. The foliage is very attractive and doesn't have significant problems with disease. This plant can spread aggressively in some situations.

Range & Habitat: White Sage is occasional in northern and western Illinois, but rare or absent in other parts of the state (see Distribution Map). Some authorities think this plant is native to Illinois (e.g., Britton & Brown), while others believe it is adventive from the west (e.g., Mohlenbrock). It is usually found along railroads and roadsides, and sometimes in dry upland areas of prairies. Cultivated forms of this plant can be found in flower gardens because of the attractive foliage. If this plant is native, Illinois would be at the eastern boundary of its distribution.

Faunal Associations: The flowers don't attract insects because they are wind-pollinated. White Sage has the potential to cause allergies in humans because of this pollen, but this species isn't very common within the state. Several grasshopper species feed on the foliage of White Sage (see Grasshopper Table), including an uncommon oligolectic grasshopper, Hypochlora alba (Cudweed Grasshopper), which often feeds hides in the foliage during the day. Other insect feeders include Ophraella artemisiae (Leaf Beetle sp.), Macrosiphoniella ludovicianae (Aphid sp.), and the larvae of Phaneta argenticostana (Tortricid Moth sp.); the moth larvae feed on the seedheads. Mammalian herbivores don't consume this plant because the aromatic foliage has a bitter taste. The seeds are too small to be of much interest to birds.

Photographic Location: The photographs were taken at Meadowbrook Park in Urbana, Illinois, where a small colony of plants was located in a restored prairie. The plants were not in bloom.

Comments: This variety of White Sage has striking foliage. The typical variety, Artemisia ludoviciana ludoviciana, has greener foliage with fewer white hairs. The leaves of this latter variety are supposed to be broader and more likely to have lobes or serrated margins toward the leaf tips. However, the hairiness and shape of the leaves can be rather variable for this species, regardless of the variety. Other Artemisia spp. have foliage that is more green and pinnately lobed. A few species, such as the introduced Artemisia vulgaris (Mugwort), have silvery hairs on the lower surface of the leaves, but their upper surface is predominantly green.

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Description: This herbaceous perennial plant becomes about 2½–5' tall at maturity. Initially, this plant develops an erect central stem with opposite leaves during the late spring, but during early to mid-summer it branches abundantly. The stems are light green to red, terete, glabrous, and sometimes glaucous. At intervals along these stems, there are pairs of opposite leaves. These leaves are 1½–3½" long and about one-third as much across; they are broadly elliptic to broadly elliptic-oblong in shape and smooth (entire) along their margins. The upper leaf surface is medium green or yellowish green and glabrous, while the lower leaf surface is light green, glabrous, and sometimes glaucous. Leaf venation is pinnate. When petioles are present, they are up to ¼" long, light green, and glabrous; otherwise, the leaves are sessile. Plants with sessile leaves are sometimes referred to as Apocynum sibericum. The stems and leaves contain a milky latex that is bitter-tasting and toxic. The upper stems and some lateral stems terminate in panicles of flowers spanning 1–3" across; these panicles are flat-headed to dome-shaped.

Each small flower is about 2-3 mm. across and 3-5 mm. long, consisting of 5 white petals, a light green calyx, 5 stamens, and a pistil. The petals are ovate to oval in shape and they are erect to slightly spreading; the calyx is glabrous and it has 5 triangular teeth. The branches and pedicels of the panicles are light green or light yellowish green, terete, and glabrous; individual pedicels are 2-6 mm. long. The blooming period usually occurs during the summer for about 1 month. The flowers are sweetly fragrant. Afterwards, cross-pollinated flowers are replaced by pairs of follicles (seedpods that open along one side). Mature follicles are 4-8" long, narrowly cylindrical in shape, and dark brown. These follicles eventually split open to release their seeds to the wind. Individual seeds are 4-6 mm. long, linear in shape, and brown; they have tufts of white hair at their apices that help to carry them aloft. The root system is long-rhizomatous, often producing clonal colonies of plants.

Cultivation: The preference is full sun and wet to mesic conditions. This weedy plant adapts to mildly acidic to alkaline soil containing loam, clay-loam, or clay-gravel. It readily tolerates flooded conditions during the spring, while tolerating drought later in the year. By late summer, the lower leaves of this plant turn yellow and begin to fall off as its condition steadily deteriorates. In moist open areas, clonal colonies can spread aggressively from underground rhizomes.

Range & Habitat: The native Common Dogbane occurs in every county of Illinois, where it is quite common (see Distribution Map). Habitats include wet prairies, prairie swales, soggy thickets, moist meadows along rivers, edges of swamps, seasonal wetlands in open areas, abandoned fields, poorly drained areas along fence rows, poorly drained areas in vacant lots, poorly drained areas in junkyards, roadside ditches, and gravelly depressions along railroads. Common Dogbane is usually found in degraded wetlands that have a history of disturbance. It is a pioneer species of such habitats.

Faunal Associations: The abundant nectar of the flowers attracts many kinds of insects, including cuckoo bees (Nomada spp.), Halictid bees, plasterer bees (Colletes spp.), masked bees (Hylaeus spp.), Sphecid wasps, Syrphid flies, bee flies (Bombyliidae), Tachinid flies, Calliphorid flies, butterflies, skippers, and beetles (Robertson, 1929). These insects vary in how effectively they cross-pollinate the flowers. The larvae of several moths feed on Common Dogbane, including the Delicate Cycnia (Cycnia tenera), Oregon Cycnia (Cycnia oregonensis), Six-spotted Gray (Spargaloma sexpunctata), and a Gracillariid moth (Marmara apocynella); see Wagner (2005), Covell (1984/2005), and Needham et al. (1928). Larvae of the last moth bore through the stems of this plant. Other insect feeders include larvae and adults of the Dogbane Beetle (Chrysochus auratus), larvae of the Red Milkweed Beetle (Tetraopes tetrophthalmus), larvae of the Dogbane Flower Midge (Clinodiplosis apocyni), the Large Milkweed Bug (Oncopeltus fasciatus), and an aphid (Aphis asclepiadis); see Clark et al. (2004), Yanega (1996), Felt (1917), Hoffman (1996), and Hottes & Frison (1931). Mammalian herbivores usually avoid the consumption of Common Dogbane because the bitter foliage contains cardiac glycosides and other toxic compounds.

Photographic Location: A fence row near Urbana, Illinois, and a remnant prairie along a railroad in Savoy, Illinois.

Comments: Another common name for this plant is Indian Hemp, because native Amerindians obtained strong silky fibers from the stems. These fibers were used as twine in basketry, mats, netting, rope, and other artifacts. Some early French explorers remarked upon the abundance of this plant in the original prairie, which they referred to as 'hemp' in their writings. Common Dogbane (Apocynum cannabinum) can be distinguished from a similar species, Spreading Dogbane (Apocynum androsaemifolium), by its smaller flowers with more erect petals. The flowers are Spreading Dogbane are about 6-8 mm. long and similarly across; their petals are ascending, rather than erect, and the tips of their petals are recurved, rather than straight. Unlike Common Dogbane, Spreading Dogbane is typically found in upland habitats where the soil is more sandy and/or acidic.

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Description: This perennial wildflower produces basal leaves about ½' tall and flowering stems about ¾-2' tall. The basal leaves are 3-6" long and similarly across. Each basal leaf is deeply divided into 3-5 primary lobes that are more or less oblanceolate in shape; each primary lobe is subdivided into 2-3 secondary lobes. In addition to their lobes, the basal leaves have scattered dentate teeth along their margins. The upper blade surface of these leaves is medium to dark green and either hairless or sparsely short-hairy, while the lower blade surface is pale green and sparsely hairy, especially along the veins. The petioles of the basal leaves are about 4-8" long, light green, terete, and hairy. The flowering stems produce pairs of opposite leaves (leafy involucral bracts) in 1-2 tiers. The opposite leaves are similar to the basal leaves, except they are sessile; leaves of the second tier are also smaller in size. The stems are light green, terete, and hairy. Above each tier of opposite leaves, 1-3 flowers are produced from pedicels about 2-4" long. Each flower is 1-1½" across, consisting of 5 white petaloid sepals, a cluster of pistils, and numerous stamens with yellow anthers. The pedicels are light green, terete, and hairy.

The blooming period occurs from late spring to mid-summer for about 1-1½ months. Afterwards, each flower is replaced by a cluster of achenes. The achenes have bodies about 4-6 mm. long and a little less across, while their beaks are 2-6 mm. long; they are also flattened and slightly hairy. The root system is rhizomatous. Vegetative colonies of plants are often produced.

Cultivation: The preference is full or partial sun, moist conditions, and calcareous soil containing loam or gravelly material.

Range & Habitat: The native Meadow Anemone is occasional in northern and central Illinois, while in the southern section of the state it is rare or absent (see Distribution Map). Habitats include moist prairies, sedge meadows, openings in floodplain woodlands, woodland borders, banks of streams, and swampy areas. These habitats can be either sandy or non-sandy. Because of its attractive flowers and foliage, Meadow Anemone is cultivated occasionally in gardens.

Faunal Associations: Floral visitors include small bees (Andrenid, Halictid) that collect pollen and Syrphid flies that feed on pollen. The larvae of a fly, Dasineura anemone, form bud galls on Meadow Anemone. Another insect, Rhizoecus falcifer (Ground Mealybug), feeds on the roots. Because the foliage contains blistering agents that can irritate the gastrointestinal tract, mammalian herbivores usually avoid consumption of this plant.

Photographic Location: The Toledo Botanical Garden in Toledo, Ohio.

Comments: Meadow Anemone is similar in appearance to Thimbleweed (Anemone virginiana) and Candle Anemone (Anemone cylindrica), except that it has larger flowers, sessile opposite leaves, and achenes that are only sparsely hairy, instead of being embedded in a cottony mass of hairs. In addition to these three species, other native species of this genus in Illinois are smaller plants that bloom earlier in the year. Another common name of Anemone canadensis is Canada Anemone.

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Description: This perennial plant is usually 1-2' tall, but sometimes it becomes considerably higher; this plant often branches in the upper half. The stems are are pale green, terete, and pubescent-hairy; they have vertical lines of fine hairs. Both alternate and opposite leaves occur along the length of the central stem. The leaves are up to 5" long and 2" across; they are lanceolate in outline, but their structure is primarily simple-pinnate (although some leaves may be double-pinnate with secondary lobes that are few in number and small in size). The primary lobes are narrowly lanceolate or lanceolate in shape and shallow to moderately deep, tapering to blunt narrow tips; the sinuses between the lobes are either flat or concave. Depending on the local ecotype, these lobes are widely spaced along the leaf margins, or they are more abundant and crowded. The leaf margins are toothless or nearly so, and they are either flat or somewhat elevated. Both the upper and lower leaf surfaces are grayish green or whitish green and more or less covered with short fine pubescence.

Western Ragweed (Ambrosia psilostachya) is monoecious, producing spike-like racemes of staminate (male) florets from the upper stems, while cyme-like clusters of pistillate (female) florets are produced below. The staminate racemes are 1-4" in length (becoming longer as they mature), cylindrical in outline, and whitish to yellowish green. The staminate flowerheads are produced along the entire length of their racemes, facing in all directions. Each staminate flowerhead spans 2-5 mm. across, becoming short-campanulate (short bell-shaped) during the blooming period. Each staminate flowerhead has 3-5 phyllaries (floral bracts) that are broadly ovate and pubescent; they are arranged in a single series and joined together along their lower halves. The interior of each staminate flowerhead has 4 or more staminate florets; these florets have stamens with yellow anthers. The peduncles of staminate flowerheads are 1-4 mm. long and pubescent; these flowerheads often droop from their short peduncles. Underneath a cluster of pistillate flowerheads there is a leafy outer bract up to 1¼" long. In addition, pairs of smaller outer bracts are located immediately below individual pistillate flowerheads. Each pistillate flowerhead has a cup-shaped involucre about 8 mm. long and 3 mm. across that has several tooth-like projections; this involucre consists of fused phyllaries (floral bracts) and it is pubescent. The interior of this flowerhead contains a single pistillate floret. The blooming period can occur from mid-summer to autumn, lasting about 1-3 weeks for a colony of plants. The florets are cross-pollinated by the wind. Afterwards, the pistillate florets are replaced by achenes. Mature achenes are 2.5–4 mm. long, dark brown, and obovoid in shape; each achene usually has a short beak at its apex and about 4 tiny tubercles around the edge of its upper margin. The root system is fibrous and rhizomatous. This plant often forms clonal colonies of varying size from its rhizomes.

Cultivation: The preference is full sun, mesic to dry conditions, and poor soil. Although this plant can grow perfectly well in moist fertile soil, in Illinois it is usually found on drier soil that contains significant amounts of clay, sand, or gravelly material, as this reduces competition from other ground vegetation. This plant is easy to grow, but it can become aggressive in situations that are well-drained and sunny. It doesn't appear to be bothered much by foliar disease.

Range & Habitat: Western Ragweed occurs occasionally in northern and western Illinois, while in the rest of the state it is uncommon or absent (see Distribution Map). It is unclear if this plant is adventive from the west, or native to Illinois. Habitats include upland areas of prairies, old cemeteries, areas along railroads, roadsides, abandoned fields, pastures, and barren waste areas. Western Ragweed is more common in disturbed areas, especially if the soil contains clay, sand, or gravel. Sometimes this plant is used in prairie restorations, or it shows up unexpectedly in prairie restorations as a result of contaminated seed.

Faunal Associations: The flowers are wind-pollinated and rarely attract pollen- or nectar-seeking insects. Caterpillars of the Common Pinkband (Ogdoconta cinereola), Ragweed Flower Moth (Schinia rivulosa), and other moths feed on Western Ragweed and other ragweeds (Ambrosia spp.); see the Moth Table) for a listing of these species. Such grasshoppers as the Little Pasture Grasshopper (Melanoplus confusus), Red-legged Grasshopper (Melanoplus femurrubrum), and Migratory Grasshopper (Melanoplus sanguinipes) feed on the foliage of Western Ragweed (see Grasshopper Table). These grasshoppers are an important source of food to some insectivorous songbirds and upland gamebirds. Other insects that feed on Western Ragweed include the Brown Ambrosia Aphid (Uroleucon ambrosiae), the stink bugs Chlorochroa persimilis and Chlorochroa uhleri, and such leaf beetles as Exema dispar, Microrhopala xerene, and Zygogramma suturalis. Like Common Ragweed (Ambrosia artemisiifolia), the seeds of Western Ragweed are a popular source of food for many kinds of granivorous songbirds and upland gamebirds (see Bird Table). The seeds are nutritious and remain available through the winter months. Some rodents eat the seeds, including the Thirteen-Lined Ground Squirrel (Martin et al., 1951/1961). Mammalian herbivores eat the bitter foliage of this and other ragweeds to a limited extent.

Photographic Location: Photographs were taken at the Windsor Road Prairie in Champaign, Illinois.

Comments: Like other ragweeds, the airborne pollen of Western Ragweed (Ambrosia psilostachya) can cause allergic reactions in people during the late summer and fall. This plant has high ecological value to birds, grasshoppers, and other insects. Across its range, there is some variability in the pubescence of its foliage, and in the number and shape of the primary lobes of its leaves. Western Ragweed resembles Common Ragweed (Ambrosia artemisiifolia) to some extent. However, the leaves of Western Ragweed are usually simple-pinnate, while the leaves of Common Ragweed are double-pinnate and more deeply lobed. Plants that display mixed characteristics may be hybrids of these two species.

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Description: This perennial plant is 2-3½' tall, branching occasionally near the apex. The four-angled stems are light green and glabrous to finely pubescent. The opposite leaves are up to 4" long and 2" across, and they have short petioles. The leaves are cordate to broadly lanceolate in shape and their margins are crenate to crenate-serrate. The upper surface of the leaves is conspicuously veined and dull green, while the lower surface is white and finely canescent. The foliage has an anise scent.

The upper stems terminate in spikes of flowers about 3-6" long. The small flowers are arranged in dense whorls that are crowded along the spike, although sometimes the whorls are less crowded and more interrupted. The calyx of a flower is tubular and has five teeth; it is usually dull blue-violet or a similar color, becoming more colorful toward its tips. The tubular flowers are about 1/3" (8 mm.) long, extending beyond the calyx. They are blue-violet. The corolla of a flower is divided into a short upper lip and a longer lower lip. The lower lip has 2 small lateral lobes and a larger central lobe. Exerted from the throat of the flower are 4 stamens with blue-violet anthers, and a style that is cleft toward its tip. The flowers bloom in scattered locations along the spikes for about 1-2 months from mid- to late summer. During this time, calyx of each flower remains somewhat colorful. There is no floral scent. The flowers are replaced by nutlets that are oval-shaped and smooth. The root system produces a taproot.

Cultivation: The preference is full or partial sun, and mesic to dry conditions. The soil can consist of loam, clay-loam, or contain some rocky material. Foliar disease isn't a significant problem, although some of the lower leaves may drop from the central stem in response to a drought. Occasionally, slugs and insects will feed on the leaves, creating holes. This member of the Mint family is more resistant to drought than many others.

Range & Habitat: In the wild, Anise Hyssop is rare in Illinois; it is known to occur in only Menard county in central Illinois (see Distribution Map). This species is more common in areas that lie northwest of Illinois. Typical habitats include openings in dry upland forests, upland areas of prairies, scrubby barrens, and thickets. Cultivated forms of Anise Hyssop are often grown in flower gardens; these cultivars are often hybrids and vary in their fidelity to the wild forms of this plant. In Menard county, the population of plants was likely introduced. Other populations in the wild, if they exist, are likely to be plants that have escaped cultivation.

Faunal Associations: The flowers are cross-pollinated primarily by honeybees, bumblebees, digger bees (Melissodes spp.), leaf-cutting bees (Megachile spp.), Halictid bees (Lasioglossum spp., etc.), and Masked bees (Hylaeus spp.), which seek nectar or pollen. The flowers are also visited by an oligolectic bee, Dufourea monardae, which has extended its range into Illinois. Other occasional floral visitors are Syrphid flies, bee flies, and various butterflies, skippers, and moths. Mammalian herbivores normally avoid consumption of this plant as the anise scent of the foliage is repugnant to them. The anise scent may also deter some leaf-chewing insect species.

Photographic Location: The photographs were taken of plants growing in the wildflower garden of the webmaster in Urbana, Illinois.

Comments: Because of its rarity, Anise Hyssop is not normally thought of as a prairie species in Illinois, nor does it appear in many field guides of prairie plants for the tallgrass prairie. This plant does occur in the northwestern area of the tallgrass prairie, however, with a few scattered remnant populations elsewhere. Other members of this genus are woodland species. One of them, Agastache scrophulariaefolia (Purple Giant Hyssop), has flowers with similar coloration to Anise Hyssop. However, the foliage of Purple Giant Hyssop doesn't have an anise scent and the the undersides of its leaves are green, rather than white. Purple Giant Hyssop is more pubescent or hairier than Anise Hyssop, and it tends to be a taller plant. The calyx of each flower remains green for this species, unlike Anise Hyssop, where each calyx assumes a coloration that is more similar to the flowers. This latter characteristic can cause Anise Hyssop to look like it is in flower, even when it is not.

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Description: This plant is a summer annual about 1-2' tall that usually branches abundantly. It is more or less erect. The slender stems are rather angular with flat ridges, green to reddish purple, and hairless to mostly hairless. The opposite leaves are up to 3" long and 1/8" (3 mm.) across; they are green to purplish/reddish green, linear, glabrous, and sessile.

Individual flowers and their buds are produced from the axils of the leaves on the upper and outer stems; these flowering stems can be regarded as leafy racemes. The swollen flower buds are conspicuously white. Each flower is about ½–¾" across, consisting of a short tubular corolla with 5 petal-like lobes and a tubular calyx with 5 short teeth. The corolla is pink, purplish pink, or medium purple; its 5 rounded lobes are quite large in relation to its tubular base. The lobes are finely ciliate along their margins. The lower interior of the corolla has dark purple spots and a pair of faint yellow lines. Near the upper interior of the corolla, there are 4 stamens with hairy white anthers and an undivided white style (sometimes with a pale yellow tip). The slender pedicels of the flowers are green to reddish purple; they are usually as long or longer than the flowers (at least ½" long). The blooming period occurs during the late summer or early fall and lasts about 2-3 weeks. Each flower lasts only a day or two before its corolla falls to the ground. There is no noticeable floral scent. Each flower is replaced by a globoid seed capsule containing many small seeds that can be blown about by the wind. The root system is fibrous. Slender False Foxglove is partially parasitic on other plants.

Cultivation: The preference is full or partial sun, moist to slightly dry conditions, and a rather loose, friable soil containing silt or sand that is slightly to moderately acidic. This species also adapts to thin rocky soil. Its growth is more robust when a suitable host plant is present nearby.

Range & Habitat: Slender False Foxglove is occasional throughout Illinois, where it is native. Habitats include moist to mesic prairies, sand prairies, savannas, sandy savannas, woodland borders, sandstone glades, thickets, low sand flats, silty or sandy roadside ditches, and edges of fields. This species tends to occur in slightly disturbed habitats with infertile soil and sparse ground vegetation. It has low fidelity to any particular habitat.

Faunal Associations: The nectar of the flowers attracts long-tongued bees (bumblebees, honeybees, and Large Leaf-Cutting bees), Panurgine bees (Calliopsis andreniformis & others), and butterflies. Some Halictid bees collect pollen, while Syrphid flies occasionally feed on the pollen. Large Leaf-Cutting bees (Megachile spp.) sometimes cut the petals (lobes) of the flowers for nesting material. Among these various insects, the long-tongued bees and Panurgine bees are more effective at cross-pollination of the flowers (see Robertson, 1929). The caterpillars of the butterfly Junonia coenia (Buckeye) feed on the foliage. Mammalian herbivores may browse on the foliage of Slender False Foxglove, although it is reportedly toxic to sheep.

Photographic Location: The edge of a field in Vermilion County, Illinois. This species was also growing along the roadside in the same area.

Comments: Slender False Foxglove is very showy during the short period in which it is in full bloom. This is the most common and widespread Agalinus sp. in Illinois, probably because it can adapt to a broad range of habitats. There is some variation in the length of the leaves, the presence or absence of fascicled leaves, the size of the flowers, and the color of the flowers across different local populations. Such minor variations have led to the description of different varieties and even different species by some authorities. Generally, Slender False Foxglove differs from many other Agalinus spp. by having flowers with shorter corolla tubes and longer pedicels. In contrast, Agalinus purpureus (Purple False Foxglove) has more elongated flowers (up to 1" long) and shorter pedicels (less than ¼"). Slender False Foxglove also has darker foliage (green to reddish purple) and darker seeds than some Agalinus spp. Members of this latter group (e.g., Agalinus skinneriana) have pale green to yellowish green foliage and pale-colored seeds.

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Description: This annual plant is 1–2½' tall, branching occasionally. It has a tendency to sprawl in the absence of supportive vegetation. The dark green stems are grooved and hairless. The opposite leaves are 1-3" long, dark green, and linear. They have smooth margins and a prominent midvein. The leaves are usually hairless, although new growth may be slightly pubescent. Secondary leaves may develop from the axils of the primary leaves along the central stem, but they are smaller in size than the latter. Some of the upper stems develop racemes of flowers. These flowers are up to 1" long and across, and vary in color from lavender to purple.

The corolla of each flower is tubular and has 5 spreading lobes that are ciliate, consisting of 2 upper lobes, 2 sides lobes, and a lower lobe. Within the throat of the corolla there are specks of dark purple and 2 patches of pale yellow. There are abundant white hairs within the corolla where the reproductive organs are located. The anthers are pale yellow and the narrow style is white. The green calyx is tubular and divided into 5 triangular lobes. These lobes are one-half the length of the calyx tube or less. The calyx is hairless and has little or no reticulation. The blooming period occurs from late summer until the fall, and lasts about a month. There is no noticeable floral scent. After the flowers are fertilized and wither away, there develops rounded capsules that are a little longer than the calyx tube. These capsules contain numerous tiny seeds. When the capsules split open at the top, gusts of wind can distribution the seeds a considerable distance. The root system is fibrous and possibly parasitic on other species of plants. Purple False Foxglove spreads by reseeding itself, and does not reproduce vegetatively.

Cultivation: The preference is full or partial sun, and moist soil that is sandy or peaty. Because the seeds are small, young plantlets may wither away if they are allowed to become too dry. A soil with an acid pH is preferred.
Stem & Leaves
Range & Habitat: Purple False Foxglove occurs occasionally throughout Illinois (see Distribution Map), where it is native. This is one of the more common Agalinis spp. in the state. Habitats include moist sand prairies, sandy savannas, paths and openings in sandy woodlands, boggy areas, and interdunal sandflats near Lake Michigan. This plant appears to thrive in areas with occasional disturbance as this removes some of the competing vegetation.

Faunal Associations: Bumblebees, digger bees (Melissodes spp.), and leaf-cutting bees (Megachile spp.) visit the flowers for nectar and pollen. The caterpillars of the butterfly Junonia coenia (Buckeye) feed on the foliage. A flea beetle, Kuschelina fallax, feeds on a very similar species, Agalinis fasciculata (Beach False Foxglove), and it is possible that this flea beetle feeds on other Agalinis spp., including Purple False Foxglove. Very little appears to be known about the relationships of these plants to mammalian herbivores as sources of food.

Photographic Location: Along a path in a sandy savanna at Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois, where this plant species is locally abundant.

Comments: The flowers are quite attractive and produced in abundance during the late summer or fall. At one time the scientific name for this species was Gerardia purpurea, but the purple-flowered false foxgloves were reassigned to the genus Agalinis, while the yellow-flowered false foxgloves were reassigned to the genus Aureolaria. Distinguishing the different Agalinis spp. can be tricky as they have similar foliage and flowers. Purple False Foxglove has larger flowers (up to 1" long and across) than some other Agalinis spp. and they occur on pedicels (flowering stalks) that are shorter than the tubular calyx (the pedicels are about 1/8" long). The flowers are always some shade of purple or lavender, while the flowers of some Agalinis spp. are often pinkish in appearance. Purple False Foxglove is quite similar in appearance to Agalinis fasciculata (Beach False Foxglove), however this latter species has secondary leaves that are nearly as large as the primary leaves (i.e., the leaves appear to be whorled along the major stems). If they are present, such secondary leaves are smaller in size than the primary leaves in Purple False Foxglove.

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2017年08月04日

Basic file parts of fertilizer
The three basic elements of any fertilizer are Nitrogen (N), Phosphorous (P) and Potassium (K), with each element serving different purposes. Nitrogen increases growth of leaves and stems (growth above ground), Phosphorus encourages healthy root growth and growth of fruits and flowers, Potassium promotes overall plant health. Different ratios of NPK are being used for different trees at different times of year, which is very important to take into account when fertilizing Bonsai.

When should I apply fertilizer?

Fertilize during the entire growth season of the tree; from early spring till mid autumn. Indoor trees can be fertilized around the year. Although sometimes disputed, do not fertilize repotted trees for about a month; also do not fertilize sick trees.

Which fertilizer to choose?

It is very important to choose the right fertilizer for your Bonsai plants: during the early spring time use a fertilizer with a relatively high Nitrogen content (something like NPK 10:6:6) to boost the tree’s growth. During the summer use a more balanced fertilizer (like NPK 6:6:6) while during the autumn use a fertilizer to harden off the tree for the coming winter (like NPK 3:6:6).

A few exceptions are worth pointing out: to encourage Bonsai to flower use a fertilizer with a high Phosphorous (P) content (like NPK 6:10:6) and for older trees you might want to use fertilizer with a slightly lower Nitrogen (N) content or reduce the quantity of fertilizer applied.

Although “Bonsai fertilizer” is fertilizer like any other, buying from (online) Bonsai shops will help you find the right NPK values. Any fertilizer with the right NPK value is perfectly fine. You can choose to use either liquid or solid fertilizer; which doesn't matter much, just follow the application guidelines as stated on the product’s packaging.

How to fertilize Bonsai trees?

Feed your Bonsai using the quantities and frequency as stated on the fertilizer’s packaging. You can choose to reduce the recommended quantity slightly for trees that are not in training anymore, to balance their growth instead of stimulating it. When using solid fertilizer it helps to use fertilizer covers, which make sure the fertilizer stays in place. Never overfeed your trees, as this will have serious consequences for their health.

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2017年08月04日

Succulents are booming in popularity for two simple reasons: they are beautiful and nearly indestructible.
Technically, a succulent is any plant with thick, fleshy (succulent) water storage organs. Succulents store water in their leaves, their stems or their roots. These plants have adapted to survive arid conditions throughout the world, from Africa to the deserts of North America. Fortunately for us, this adaptive mechanism has resulted in an incredible variety of interesting leaf forms and plant shapes, including paddle leaves, tight rosettes, and bushy or trailing columns of teardrop leaves.

As a group, succulents include some of the most well-known plants, such as the aloe and agave, and many almost unknown plants. Cacti are a unique subset of the succulent group. Succulents make excellent display plants in dish gardens.
The Rules for Growing Succulent Houseplants
No matter what kind of succulent you're growing, the rules are pretty similar between the different species. Here are the general rules for growing top-quality succulents:
Southern Light
Succulents prefer bright light, such as found on a south-facing window. Watch the leaves for indications that the light level is correct. Some species will scorch if suddenly exposed to direct sunlight. The leaves will turn brown or white as the plant bleaches out and the soft tissues are destroyed. Alternatively, an underlit succulent will begin to stretch, with an elongated stem and widely spaced leaves. This condition is known as etoliation.

The solution is to provide better light and prune the plant back to its original shape. Many kinds of succulents will thrive outdoors in the summer.
Temperature
Succulents are much more cold-tolerant than many people assume. As in the desert, where there is often a marked contrast between night and day, succulents thrive in colder nights, down to even 40ºF.
Ideally, succulents prefer daytime temperatures between 70 F and about 85 F and nighttime temperatures between 50 F and 55 F.
Watering
Succulents should be watered generously in the summer. The potting mix should be allowed to dry between waterings, but do not underwater. During the winter, when the plants go dormant, cut watering back to once every other month. Overwatering and ensuing plant rot is the single most common cause of plant failure. Be aware, though, that an overwatered succulent might at first plump up and look very healthy. However, the cause of death may have already set in underground, with rot spreading upward from the root system. A succulent should never be allowed to sit in water. The following are signs of under- or overwatering:
Overwatering. Overwatered plants are soft and discolored. The leaves may be yellow or white and lose their color. A plant in this condition may be beyond repair, but you can still remove it from its pot and inspect the roots. If they are brown and rotted, cut away dead roots and repot into drier potting media, or take a cutting and propagate the parent plant.
Under-watering: Succulents prefer generous water during the growing season (spring and summer). An under-watered plant will first stop growing, then begin to shed leaves. Alternatively, the plant may develop brown spots on the leaves.

Potting Soil
Succulents should be potted in a fast-draining mixture that's designed for cacti and succulents. If you don't have access to a specialized mix, consider modifying a normal potting mix with an inorganic agent like perlite to increase aeration and drainage. These plants have shallow roots that form a dense mat just under the soil surface.
Fertilizer
During the summer growing season, fertilizer as you would with other houseplants. Stop fertilizing entirely during the winter.

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Family - Asteraceae
Stems - To 1.5m tall, erect, herbaceous, glabrous, glaucous, hollow, with milky sap, branching above in inflorescence, single from stout taproot or stolons.
Leaves - Alternate, sessile, clasping, glabrous, dentate (the teeth with minute prickle tips), to +30cm long, reduced above. Lower leaves lyrate pinnatifid. Upper leaves oblong-linear.

Inflorescence - Loose corymbiform arrangement of flower heads terminating branches of inflorescence. Peduncles glabrous or with glandular pubescence. Each division of inflorescence subtended by small scalelike attenuate bract.
Involucre - Cylindrical to urceolate, to 1.4cm tall (long) in flower, 8-9mm in diameter. Phyllaries in two or three series. Outer most phyllaries small. Inner phyllaries to 1.6mm long, 2mm broad, linear, with scarious margins, spreading to slightly recurved at apex, glabrous or with glandular pubescence, with darker green midvein, appressed.

Ray flowers - Head to 5cm broad. Flowers fertile. Ligules yellow, -3cm long, 3-4 toothed at apex, glabrous. Corolla tube whitish, pubescent. Pappus of numerous capillary bristles to 1.2cm long. Achene 1mm long in flower(+3mm long in fruit), pubescent. Receptacle slightly concave.

Disk flowers - Absent.
Flowering - June - October.
Habitat - Waste ground, roadsides, railroads.
Origin - Native to Eurasia.
Other info. - This is definitely the most showy member of the genus in Missouri. The large flower heads are unmistakable. Unfortunately, the plant is introduced and should not be willingly spread. It is very aggressive and is becoming quite widespread.
Two varieties of the species can be found. Variety glabrescencs (Geunth.) Grab. & Wimm. (pictured above) has glabrous phyllaries and peduncles. A synonym for this variety is var. uliginosus (Bieb.) Nyman. Variety arvensis has peduncles and phyllaries which are glandular pubescent.

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Family - Asteraceae
Stems - To 1.5m tall, erect, herbaceous, from slightly thickened roots and horizontal rhizomes, terete, densely pubescent (at least in the middle and upper portions), retrorse pubescent near the base, simple except in the inflorescence.
Leaves - Basal rosette absent at anthesis. Cauline leaves reduced from the base of the plant to the apex, alternate, sessile. Blades lanceolate near the bottom of the plant becoming elliptic to ovate neat the apex, to +7cm long, +/-2cm broad, shallow crenate-serrate along the entire margin. Veins very impressed above giving the leaf a rugose appearance, veins expressed below. Blades scabrous adaxially and dull green, pubescent on the veins abaxially and lighter than the adaxial side.

Inflorescence - Pyramidal, paniculate arrangement of flowering branches and flower heads. Inflorescence branches pubescent, to +10cm long. Each flower head with a minute bract at the base of its peduncle. Bracts green, subulate, 1mm long. Flower heads secund on inflorescence branches. Peduncles 1-3mm long, pubescent.
Involucre - 2-4mm high (long), -2mm in diameter, light green. Phyllaries imbricate, glabrous, obtuse at the apex. Longest phyllaries to 2-3mm long, -1mm broad.

Ray flowers - 5-9 per head, pistillate. Ligule elliptic, notched at the apex, glabrous, yellow, 2mm long, 1mm broad. Corolla tube +/-2mm long, greenish-translucent, glabrous, thin. Stigmas exserted, yellowish to reddish, +?-1mm long. Pappus of capillary bristles, white, antrorse barbellate, 2-3mm long, uniseriate.
Disk flowers - +/-5 per head, perfect. Corolla 5-lobed, 2-3mm long, expanded and yellow in the apical half, contracted and greenish in the basal half, glabrous. Lobes acute, spreading, 1mm long, .6mm broad, subulate. Stamens 5, adnate at the base of the expanded portion of the corolla tube. Filaments wanting. Anthers yellow, connate around the style, partially exserted, 1.5mm long. Stigmas lanceolate, yellow, -1mm long, mostly remaining erect, exserted beyond the anthers. Pappus as ray flowers. Achene retrorse pubescent in flower. Mature achenes not seen.

Flowering - August - October.
Habitat - Wet ground of swales, swampy meadows and thickets, borders of spring branches, borders of streams, wet prairies, occasional on dry sandy knolls and ledges.
Origin - Native to U.S.
Other info. - This goldenrod species can be found in the southeast corner of Missouri. The plant can be identified by its habitat, rhizomes, pubescent stems, and sessile, rugose leaves.
Steyermark broke the species up into three varieties based on stem pubescence and inflorescence shape. These varieties are no longer valid.

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Family - Asteraceae
Stems - To 1m tall, erect, herbaceous, fro a vertical caudex and slightly thickened roots, terete, glabrescent basally, hispidulous with multicellular hairs in the apical 1/2.

Leaves - Alternate, the basal and lower-most petiolate, sessile above. Petioles of the basal leaves to +20cm long, with a very narrow adaxial groove, mostly glabrous but with some hairs in the groove. Blades to +/-20cm long, +/-8cm broad, scabrous above and below, greyish because of dense hairs below, elliptic-lanceolate, shallow serrate, acute, tapering slightly at the base. Cauline leaves sessile, quickly reduced upward, shallow crenate-serrate, densely pubescent (with a greyish cast), scabrous, those in the middle of the stem oblanceolate. Leaves in the apical 1/3 of the stem reduced to bracts, ovate to orbicular.

Inflorescence - Terminal corymbiform arrangement of flowerheads. Peduncles densely hispidulous. Each division of the inflorescence subtended by a small foliaceous bract.
Involucre - To +8mm long (tall), 5mm in diameter, cylindric. Phyllaries imbricate, appressed, unequal, the longest to 6mm long, 2mm broad, rounded at the apex, greenish (mostly at the apex), scarious below, with a green midrib, glabrous internally and externally, with ciliolate margins, oblong.

Ray flowers - Flowers 8-10 per flowerhead, fertile, pistillate. Corolla tube 4mm long, glabrous, yellowish. Ligule 4mm long, 2mm broad, yellow, glabrous or with a few sparse hairs, rounded at the apex. Style purplish, glabrous, thin, 5mm long, bifurcate. Stigmas 1mm long. Pappus of capillary bristles, white, 5mm long. Bristles antrorse barbellate. Achene green in flower, 2.2mm long, ribbed, glabrous.
Disk flowers - Disk corollas yellow, contracted and thin in the basal 2/3, expanded in the upper 1/3, 5mm long, 5-lobed, glabrous or with a few small hairs. Lobes acute, spreading, 1.1mm long. Stamens 5, adnate in the basal 1/3 of the corolla tube. Filaments glabrous, compressed, thin, glabrous, yellowish. Anthers yellow, 2.5mm long, connate around the style, partially to wholly exserted, acute at the apices. Style exserted, purplish, bifurcate for about 1mm. Stigmas erect (mostly). Pappus and achenes as the ray flowers.
Flowering - August - October.
Habitat - Prairies, glades, rocky open ground, thickets, borders of wet meadows.
Origin - Native to U.S.
Other info. - This showy species can be found throughout most of Missouri but is apparently absent in the southeast corner of the state. The plant is easy to identify in the field because of its big basal leaves and large, showy flowerheads. It has larger flowerheads than any other Solidago species in Missouri. This is a characteristic plant of prairies and is certainly worthy of cultivation as it is drought tolerant and requires little care.

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