YUCCA, the name of a genus of shrubs with clustered ensiform leaves, belonging to the bhareer, but also employed as a common name to designate the plant: to the entire botanical family of yuccas. includes n. • only the genus Yucca but several other genera. as Sammella, Clisroyucco, Hester-alit. etc. The species are chiefly found in the United States and Mexico. though some of them are (Es tnbuted to many portions of the world The best known species in the United States is Yucca ftlasotostosa. or Adam's needle, which is found in cultivations as far north as New Eng land, its clusters of large white, bell-shaped flowers making it a favorite in gardens. Until recently none of the species has been regarded as valuable commercially, although the coarse fibre of Y. called bear-grass, has long been used in a small way as tie material in the south. In Mexico, however, there are several species with larger leaves that have of late years been exploited for their fibre, which is becoming known as a rather coarse substitute for the better cordage fibres. Yncea qaustrulis, Hesperatot funifera and Samuella carnerosana especially are used in northern, eastern and cen tral Mexico for fibre, which is derived from the cogolla or central spike of unopened leaves, the cogolias first being steamed, and the individual leaves scraped with a dull-edged iron tool, upon a block of wood, and the fibre extracted. This coarse fibre is known as patina istle, pita syl vestris, zainandoque, etc. Yucca fibre is stiff,
harsh and brittle, and as prepared is not always of good color, and therefore can never take rank with the better fibre known as hard cord age fibres. (See From). Yucca baccata yields a fairly good fibre, and the parenchyma or pith, and the root possess detergent qualities, from which the name soap-plant has been derived. The sun-cured, whitish yellow inner leaves of Yucca glauca are used by the Arizona Indians for ornamental basketry, either entire or sub divided and several other species are also em ployed in the domestic economy of North American Indian tribes for rude cordage, bas kets, sandals, mats, etc.
A very remarkable feature in the yucca is its fertilization by the aid of any of several spe cies of small whitish moths of the tineintne genus Pronuba. The yucca flowers are so shaped as to be impossible of fertilization, and no other insects attach themselves to this plant. The yucca moth gathers a quantity of pollen in its jaws, then lays an egg in the pistil, and stuffs the hole in which it is laid with pollen, thus fertilizing the ovary. The caterpillar de velops in the fruit-pod, but does not seriously harm the plant. This extraordinary case of symbiosis was disclosed by C. V. Riley in 1872, and may be found fully related by him in the