They feed on the nectar of various flowers, including milkweed and Indian hemp. Underbrush consists of willows, sea buckthorn, and dense growths of Indian hemp and Ural licorice. In 1940 the Commonwealth extended import restrictions on Indian hemp, including preparations containing hemp. British Guiana passed its Indian Hemp Ordinance in 1913. In 1927, the laws designed to target opium usage were finally extended to Indian hemp. Growing in many areas, Indian hemp ("Apocynum cannabinum") was harvested and dried before maturity.