Medicinal plants. Historical engraving of a series of medicinal plants. The flowers of linaria (Linaria vulgaris), for example, were once used as an ophthalmic remedy. The root of the mandragora (Mandragora officinarum) herb was widely used as a narcotic and an anaesthetic. The resin produced by the liquidambar (Liquidambar styraciflua) tree was used to treat skin diseases. The skin and blubber of the aquatic manati (manatee, Trichechus sp.), or sea cow, (bottom right) were believed to have medicinal and therapeutic properties. Dated 1752, the engraving is taken from a dictionary of simple drugs written by the French chemist Nicholas Lemery (1645-1715).