The flower of this native plant has a form similar to that of other milkweeds. The five petals are reflexed downwards supporting 5 incurved vertical horns. The flowers are bi-colored—a distinguishing trait. The petals are usually green, while the horns are white. This species can also be recognized because it has drooping flower clusters, 2-4 inches in diameter. The clusters (umbels) arise from the leaf axils. Often these clusters are more open than those of common milkweed. The flowers attract bumblebees and butterflies. The seed pods are about 6 inches long, and ¾ inch wide. When mature, it splits open to release tufted seeds into the air.

The leaves are stalked and pointed at both ends. The leaves are widely spreading and about the same size all the way up the stem. Each is about 6 inches long and 3 inches wide. Due to weight, they are also often drooping. Like most milkweeds, the sap is a milky latex-like fluid. Caterpillars of several species of butterflies, including the Monarch, feed on the leaves. The toxic nature and bitter taste of the foliage usually cause herbivorous animals to avoid the plant. The plant grows 2-6 feet tall in open woods or woods edges. It grows best in partial sunlight. It is the most shade-tolerant of the milkweeds. The stems are green or purple.

It is a perennial through most of its range, though in colder northern areas it can be a fast-growing annual. The blooming period is June to August. It can be planted in wildflower gardens. Because it is a host for the Monarch butterfly, its growth should be encouraged.