COMMON MILKWEED (Asclepias syriaca) скачать в хорошем качестве

COMMON MILKWEED (Asclepias syriaca)

How to Identify Common Milkweed (Asclepias syriaca) This plant is Common Milkweed, a member of the milkweed family that is native to North America. It is a perennial that flowers in midsummer. The plant has tall, thick, unbranched stems that are smooth and light green to purple in color. The majority of the plant is sparsely covered in fine, white hairs. The leaves grow opposite each other along the stem, and are oblong to lance-shaped with smooth, wavy margins. The prominent midrib, veins, and petiole are often colored red. The upper surface of the leaves is smooth and dark green, while the underside is light green and is soft and velvety. The plant produces spherical umbels of pink, purple or white flowers that have a distinctive, star-like shape and strong sweet odor. These will produce large elongated follicles up to 5” in length that have a softly spined, fleshy outer coating. These will mature to a dark brown and split open when dry, revealing flat red or brown seeds that are attached to large tufts of fibers. The plant has a thick, deep taproot and large spreading rhizomes that allow it to create dense stands. The whole plant is filled with a milky latex sap, which will profusely gush out when the plant is damaged. Common milkweed needs full sun and grows in a variety of soil conditions and moisture levels. It is common along cultivated fields, roadsides, ditch banks, and in pastures, meadows, and prairies. The plant is toxic to livestock if eaten as it contains large amounts of glycosides, but its effects on humans is debated. It is an important source of food for many different insects, and is the exclusive food of Monarch Butterfly caterpillars. Common Milkweed can be confused with Showy Milkweed, but can be distinguished as Showy Milkweed has a much denser coating of silvery-white hairs. Common milkweed will readily hybridize with other milkweed species. The plant is somewhat invasive, and has become naturalized in Europe. It can be aggressive and difficult to manage, but cannot withstand tillage and root disturbance. Sources: Weeds of the West, 5th Edition (1991) by Tom D. Whitson, published by the Western Society of Weed Science University of California Agriculture and Natural Resources IPM – Weed Gallery http://ipm.ucanr.edu/ United States Department of Agriculture – Plant Database https://plants.usda.gov