Apocynum cannabinum (dogbane, amy root, hemp dogbane, prairie dogbane, Indian hemp, rheumatism root, or wild cotton) is a perennial herbaceous plant that grows throughout much of North America—in the southern half of Canada and throughout the United States. It is poisonous to humans, dogs, cats, and horses. All parts of the plant are toxic and can cause cardiac arrest if ingested. Some Lepidoptera feed on this plant, such as a hummingbird moth. Description Apocynum cannabinum grows up to tall. The stems are reddish and contain a milky latex. The leaves are opposite, simple broad lanceolate, long and broad, entire, and smooth on top with white hairs on the underside. It flowers from July to August, has large sepals, and a five-lobed white corolla. The flowers are hermaphrodite, with both male and female organs. Taxonomy Etymology Apocynum means "poisonous to dogs". The specific epithet cannabinum, and the common names hemp dogbane and Indian hemp refer to its similarity to Cannabis as a source of fiber. It likely got its name from its resemblance to a European species of the same name. It is called qéemu in Nez Perce and in Sahaptin. The Maidu Concow people call the plant pö (Konkow language). Distribution and habitat Apocynum cannabinum grows in open wooded areas, ditches, and hillsides. It is found in gravelly or sandy soil, mainly near streams in shady or moist places. It is native to much of North America—in the southern half of Canada and throughout the United States. Ecology In gardens, the species can be unwanted, sprouting from spreading roots. When growing among corn, Apocynum cannabinum can reduce yields by up to 10%, and among soybeans by up to 40%. It can be controlled through mechanical means, although it is difficult to control with herbicides. The plant serves as a larval host for the snowberry clearwing (Hemaris diffinis), which is a pollinator that resembles a small hummingbird. It is also a host plant for the dogbane tiger moth (Cycnia tenera) and the zebra caterpillar (Melanchra picta). The larvae of Marmara apocynella feed on the stems, making a "long whitish serpentine mine". Toxicity It is poisonous to humans, dogs, cats, and horses. All parts of the plant are toxic, and the plant contains cardiac glycosides. The stems contain a white sap capable of causing skin blisters. Uses Fiber The stalks of Apocynum cannabinum have been used as a source of fiber by