Cannabis plant. Historical artwork of the hemp or cannabis plant (Cannabis sativa). Small grey fruit (achenes, upper left) contain green seeds. The leaves and the female flowers are used to produce the psychoactive drug marijuana. Despite medicinal uses the drug is banned in most countries. Hemp fibre and seed oil also come from this plant. From The Instructive Picture Book or Lessons from the Vegetable World, Charlotte Mary Yonge, 1857.