soap plant

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several bulbous plants of the genus Chlorogalum of western North America, having small white or purple flowers. The edible bulbs of several species, especially C. pomeridianum, produce a soapy lather when crushed.
2. n. Any of various plants having parts used as soap.

Century Dictionary and Cyclopedia

1. n. One of several plants whose bulbs serve the purpose of soap; particularly, the Californian Chlorogalum pomeridianum, of the lily family. It is a stout brownish plant, from 1 to 3 feet high, with long linear leaves and a spreading panicle of white flowers. The bulb, which is from 1 to 4 inches thick, when divested of its coat of dark-brown fibers, produces, if rubbed on wet cloth, a thick lather, and is often substituted for soap. Also called soap-apple and soap-bulb, and, together with some plants of a similar property, by the Mexican name amole. Zygadenus Fremontii, also Californian, is another soap-plant.

GNU Webster's 1913

1. n. (Bot.) one of several plants used in the place of soap, as the Chlorogalum pomeridianum, a California plant, the bulb of which, when stripped of its husk and rubbed on wet clothes, makes a thick lather, and smells not unlike new brown soap. It is called also soap apple, soap bulb, and soap weed.