20. Urticaceae.—Nettle Family.
A large and very diversified family, consisting of herbs, shrubs, or trees, sometimes with a milky juice yielding caoutchouc; some species have a bark which yields mucilage; the nettleworts are remarkable for the caustic secretion of their glandular stinging-hairs; the juice of the hempworts (suborder Cannabineae) is bitter and narcotic.
A Manual of Organic Materia Medica and Pharmacognosy, 1917, was written by Lucius E. Sayre, B.S. Ph. M.