Indian hemp, (species Apocynum cannabinum), North American plant of the dogbane family Apocynaceae (order Gentianales). It is a branched perennial that grows up to 1.5 m (5 feet) tall and has smooth opposite leaves and small greenish white flowers. Indians used the fibres from the stem to make bags, mats, nets, and cordage. Its milky juice, or latex, yields rubber, and the dried roots of Indian hemp and a related plant (A. androsoemifolium) make a drug that acts as a heart stimulant. True hemp (Cannabis sativa) is sometimes called Indian hemp.