woolly milkweed

not listed

N4? - Apparently Secure

not listed

Woolly milkweed is a 6″ to 12″ tall, weekly erect, perennial forb that rises on a single stem. The leaves and stems contain a milky juice.

The stem is covered with long, soft shaggy, but unmatted hairs.

The leaves are alternate, lance-shaped, 1½″ to 2¾″ long, and have blunt tips. They are sparsely covered with long, soft shaggy, but unmatted hairs on both sides. The margins are untoothed, thickened, and rough to the touch.

The inflorescence is a single dense, umbrella-shaped cluster (umbel) at the end of the stem. The cluster is erect or drooping on a short stalk.

The structure of the typical milkweed flower is unique and instantly recognizable. There are 5 petals bent backward at the base and hanging downward. Subtending the petals are 5 much shorter, light green, lance-shaped sepals. There are 5 stamens. Formed from the filament of each stamen is a petal-like appendage. The appendage consists of a tubular hood surrounding an awl-shaped horn in the center of the hood. The stamens and the stigma are fused together into a crown-like structure (gynostegium). Each stigma has a long slit designed to catch the legs of a pollinating insect. A small, dark, sticky gland above this slit is attached to pollen sacs from adjacent anthers. These glands are designed to break off as an insect pulls its leg free of the slit, and remain attached to the insects leg. The flowers are pollinated by larger insects strong enough to lift off with the pollen sacs attached. Smaller insects are caught in a death trap or leave behind their detached legs.

The flowers of this plant are shaped like the typical milkweed flower. They are ¼″ to ⅓″ tall, ⅓″ wide, and are attached on ¼″ to ½″ long thread-like stalks. The petals are greenish-yellow or somewhat purplish. They bend backward at the base, hang downward, then curl upward near the tip. They are attached directly below the hoods without a separating column. The hoods are the same color as the petals. They have no horns.

The fruit is a spindle-shaped pod. It opens on one side exposing the seeds to spreading by the wind. The seeds have a tuft of whitish hairs at the tip.

6″ to 12″

Greenish-yellow or somewhat purplish

Dry. Prairies, upland woods.

June to July

Milkweeds are the only plants that Monarchs lay their eggs on. The eggs are laid on the underside of healthy young leaves.

This and other milkweeds contain cardiac glycosides and may be poisonous to both humans and livestock.

Sources

2, 3, 4, 5, 28, 29, 30.

Native