Spreading dogbane, also called fly-trap dogbane, is a perennial herb of North America, common across Canada and most of the United States and reaching into north-east Mexico. It grows in woods and along their edges, on prairies, in meadows and fields, and favours dry soil at low to middle elevations. It stands twenty to thirty centimetres tall, now and then half a metre, on branching, hairless stems that bleed a milky sap when broken, with pointed oval leaves that are hairy beneath. Pairs of pink flowers open at the tips of the stalks from June to September and give way to paired pods, roughly twelve to eighteen centimetres long, packed with silky-haired seeds. The genus name joins Greek words for 'away from' and 'dog', after its poisonous effect on dogs, and animals in general leave it alone. Native Americans put it to many uses: as medicine for a long list of complaints, the Ojibwe taking the root during the medicine lodge ceremony, and its strong stem fibres as sewing thread. Medical writers of the late nineteenth and early twentieth centuries recorded that it nearly always caused nausea or vomiting and heavy sweating and acted powerfully on the heart. Its magical use is narrow: Cunningham gives it one power, love, and puts its flowers in love mixtures.