This species is found commonly in and about swamps from July to September and ranges through New Brunswick to Tennessee, Kansas, and Louisiana. The usually smooth stalk is slender and branched. It is leafy to the top, and grows from two to four feet high. The leaves are long lance-shaped, tapered at the apex and narrowed toward the base, where they are sometimes slightly heart-shaped. The veins are ascending and not spreading as in the preceding species. Neither has this plant an abundance of milky juice. The leaves grow in alternating pairs, and are set on short stout stems. The numerous flowers are arranged in several rather small, loose terminal and flat-topped clusters. They are not large and the corolla is red or rose-purple, rarely white. The lobes are oblong, and the pink or purplish hoods are shorter than the enclosed, incurved horns. The stems of the slender pods are not crooked.
The Hairy Milkweed, A. pulchra, is a more northern species with shorter stemmed, broader leaves, and lighter coloured flowers. It is more or less hairy, and the stalk is stout. It ranges from Maine to Minnesota and south to Georgia.