Flower:

Flowers are in rounded clusters 1 to 3 inches across that arise from the leaf axils in the upper part of the plant, and at the top of the plant. Each cluster usually has 10 to 20 flowers. Individual flowers are about ¼ long, have a 5-parted crown with a curved horn projecting out of each of the 5 short hoods, arching over the tall column in the center. 5 light green petals bent downward and flare out beneath.

Leaves and stem:

Leaves are up to 3 inches long and very narrow, less than 1/8 inch wide, with a prominent central vein. Whorls of 3 to 6 leaves are densely packed along the stem but spread out as the plant matures. Leaves initially point up but become more horizontal or turned downward with age. The stem is slender and has fine hairy lines that extend down from the base of the leaves.

Fruit:

Fruit is a spindly pod 3 to 4 inches long containing numerous flat brown seeds, each with a tuft of white hair to carry it off in the wind.

Notes:

All Asclepias were formerly in family Asclepiadaceae but have been reassigned to Apocynaceae (Dogbane).