Asclepias exaltata
Asclepias exaltata
Asclepias exaltata (English poke milkweed ) is a plant of the genus milkweed ( Asclepias ) from the subfamily of milkweed plants ( Asclepiadoideae ).
- 4.1 Literature
- 4.2 Notes and references
Features
Vegetative characteristics
Asclepias exaltata is a perennial plant with a fleshy, whitish taproot. The herbaceous shoots die each year from after the growing season and drive in the following year from the taproot new. Per rootstock or taproot only one engine is formed in most cases. This is comparatively strong, unbranched and 40 to 100 cm, under very favorable site conditions and up to 180 cm high. The shoots are bare, or from the node running lines with inconspicuous fluffy hair down the shoots. The stalked leaves are arranged on opposite sides. The stems are 0.5 to 1.5 cm long. The thin, membranous leaf blades are ovate to elliptic, or oblong- elliptic with a short, narrow tip; the base is broadly rounded. They are 10 to 20 cm long, sparsely pilose 2 to 11 cm wide and on the top or bare; the underside is gray-green and hairy. The veins have a slight purple tint; they stand out clearly by the green of the leaf blade from.
Inflorescence and flowers
The solitary, drooping inflorescences are approximately terminally to the uppermost nodes present. They are little - to many flowered (up to 10 flowers ) and relatively open, and have a rigid 0.3 to 8.5 cm long, purple stem. The fivefold hermaphrodite flowers are zygomorphic, and have a double perianth. The flower stem is slender and 3 to 5 cm. The flowers are of medium size with ovate - lanceolate, about 5 mm long, bare sepals. The corolla is wheel-shaped with reflexed Kronblattzipfeln. The 8 to 12 mm long tail are whitish with a pink or purple tint. The single-row, whitish corona is short-stalked, the short stem verkehrtkonisch to cylindrical and about 2 mm long and as wide. The 3.5 to 4 mm long tip of staminal corona are tubular - shaped hood reformed and more or less distinctly denticulate at margins. The horn-shaped secondary extension leans in below the middle to the tip of the corona at, is about twice as long as this, and bend over the stylus head together. The stylus head is cylindrical, 3 to 3.5 mm long and wide. The flower produces abundant nectar and radiates to the human nose a rather unpleasant smell.
Fruit and seeds
The follicles stand upright on curved stems and are schmall - spindle-shaped, 12-15 cm long and 1.5 to 2 cm wide. They are smooth and hairless substantially. The seeds are broadly elliptical, 7-9 mm long, and have a white, 3 to 4.5 cm long hair.
Geographical distribution and (syn ) Ecology
The range of the species extends over wide areas of the eastern and central United States (Alabama, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Iceland, South Carolina, Tennessee, Vermont, Virginia, West Virginia and Wisconsin) as far as southern Canada (Ontario and Quebec ). The species grows in moist woods, thickets and meadows. It flowers from May to August.
The flowers attract by their abundant nectar produced numerous insects. The species is also a food plant for the caterpillars of the monarch butterfly (Danaus plexippus) and the bear Spinners Euchaetes egle.
Taxonomy and systematics
The taxon was first classified by Carolus Linnaeus in 1762. Asclepias phytolaccoides GFLyon ex Pursh (1813 ), this name is derived from the English vernacular name poke milkweed from, is a junior synonym. Asclepias exaltata is accepted by the Plant List as a valid taxon.