Scientific Name: Asclepias syriaca

Common Name: common milkweed

Other Common Names: butterfly flower, silkweed, silky swallow-wort, Virginia silkweed

Synonyms: Asclepias intermedia, Asclepias kansana

Habit: The plant tends to bloom from around June to August but the seedlings do not flower until the second year.

Leaves: Leaves are oval shaped anywhere from 10-30 cm long and 5-11 cm wide. The lower surface of the leaves contain fine hairs while the upper portion is lacking hair structures.

Identifying Characteristics: Every part of the plant, mainly the stem, excretes a white/milky sap when broken in two. The stems are initially green but as they mature they form a red tint. The plant's root structure is a taproot with a deep rhizome.

Flower Seed Head: Flowers are in clusters of approximately 20-130, located at the end of a stem which is on a long, slender stalk. They are purple to white with a greenish look.

Seed Fruit: The fruit is hairy and teardrop-shaped, which are follicles. Each fruit contains numerous seeds of about 6-10 mm in length. The seeds are flat and brown and have some silky hairs.

Where Found: The common milkweed is found mainly in the northeastern US, Virginia to Georgia, and west to the Rocky Mountains as well. The plant has been found to grow in meadows, roadsides, reduced-tillage fields, and some other open habitats.

  • Life cycle: perennial

  • Milky sap: Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Asclepiadaceae

  • Leaf arrangement: opposite

  • Leaf shape: lance

  • Ochrea: Not Present

  • Leaf margin: entire

  • Stem hairs: no hairs; has hairs

  • Flower color: purple; white

  • Growth habit: upright and nonwoody

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs

  • Flower diameter: pencil

  • Flower symmetry: radial symetery

  • Root structure: rhizomes present

  • Leaf stalk: shorter than leaf; none