Indian hemp, or dogbane, is a shrubby, upright perennial with opposite branches and milky sap. Flowers are tiny, 5-pointed bells, massed in cymes, white or greenish white, attractive to bees. Leaves opposite, smooth-edged, variable, oblong or lance-shaped, hairy or not hairy, with conspicuous petioles (stalks). Stems are reddish and often grow higher than the flower cluster.
Similar species: Spreading dogbane (A. androsaemifolium) has larger flowers in looser (less dense) clusters. Its flowers are pink or white with red inside and the petal lobes spread. The leaves tend to droop or spread. The two dogbanes live in the same habitats and can produce hybrids that can make identifications tricky.
Habitat and Conservation
Dogbane stems have a tough, fibrous bark that can be used like hemp for making rope, nets, straps, and so on. Native Americans were using it for cordage thousands of years ago. People still use it for making rope and twine, and fabric for clothing.
The milky latex sap which can potentially be used for making rubber.
When bruised, all parts of the plant exude a toxic white juice; the plant has a long list of folkloric medicinal uses.
The toxic juices make this plant inedible to most mammals, but several types of moths eat this plant as caterpillars. They build up the toxin in their bodies and become unpalatable to predators.
The delicate cycnia (Cycnia tenera), a tiger moth, is found wherever dogbane grows in Missouri. Dogbane is also is a larval food plant for the snowberry and hummingbird clearwings, sphinx moths that mimic hummingbirds.