Apocynum cannabinum

Native

Dry to moderate moisture. Prairies, roadsides, railroads, open sites.

July to August

White or greenish white

2′ to 5′

This is a 2′ to 5′ tall, erect, perennial forb rising on a single stem from a taproot and long rhizomes. It often forms colonies. The stems and leaves contain a milky juice.

The stems are erect, reddish-brown, branching above the middle, and often covered with a whitish, waxy bloom. The lower stem is hairless, the upper stem hairy.

Leaves are opposite, untoothed, and egg-shaped or roughly egg-shaped but two or more times as long as wide with more or less straight sides. They are on short leaf stalks. The stalks of the main stem leaves are ⅛″ to ⅜″ long. The leaf blades are 2″ to 4⅓″ long, up to 1½″ wide, usually erect or ascending, sometimes widely spreading, with a short, sharp, abrupt point at the tip. The upper surface is hairless and dark green. The underside is pale is usually hairy. The hairiness of the leaves is variable.

The inflorescence is a branched cluster with many flowers at the ends of the smaller stems. It usually does not extend beyond the leaves.

The flowers are ⅛″ to ¼″ wide, fragrant, and erect on flower stalks that are just over ⅛″ long.

The 5 white or greenish white petals are united at the base to form an urn-shaped cylinder with 5 lobes. The lobes are erect to spreading and do not curve backward.

The fruit is a pair of 4″ to 8″ long slender seed pods.

Spreading dogbane (Apocynum androsaemifolium) is a shorter plant. The leaves droop downward. The inflorescence usually extends beyond the leaves. The flower is larger, bell-shaped, with pink vertical stripes. The corolla lobes bend backward strongly.