Comprehensive DescriptionRead full entry
General: Milkweed Family (Asclepiadaceae). Common milkweed (Asclepias syriaca) is a perennial herb growing from a deep rhizome. The hairy stems are usually solitary from a simple to branched and thickened base, and are 6-20 dm (1.9-6.5 ft) tall. The opposite leaves have broadly ovate to elliptic blades that are 10-20 cm (3.9-7.9 in) long and 5-11 cm (1.9-4.3 in) wide. The leaves are sparsely hairy above and densely hairy below, and the petiole is 0.2-1.4 cm (0.08-0.77 in) long. The inflorescence occurs in the upper leaf axils, and there are 20-130 flowers per inflorescence. The flowers are small, 11-17 mm (0.4-0.7 in), and bloom from May to August. The five petals are green to purple-tinged, and are topped by a crown of five erect lobes that are rose to purple, rarely white. The fruits are spindle-shaped follicles covered with soft hairs. The small, round, hairy seeds are 6-8 mm (0.2-0.3 in) in diameter.
Distribution: For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. This plant grows throughout the Great Plains ecoregion from southern Canada south to NE Oklahoma, NW Georgia, and Texas, and east from North Carolina to Maine.