Any of about 40 species of succulent plants (genus Yucca ) of the lily family , native to southern North America.
Most species lack a stem and have a rosette of stiff, sword-shaped leaves at the base and clusters of waxy white flowers. The Joshua tree ( Y. brevifolia ) has a stem more than 33 ft (10 m) high. Commonly cultivated as ornamentals for their unusual appearance and attractive flower clusters are the aptly named Spanish bayonet ( Y. aloifolia ), Spanish dagger ( Y. gloriosa ), and Adam's needle, or bear grass ( Y. filamentosa ). Yucca moths (genus Tegeticula ) inhabit yucca bushes, each moth species adapted to a particular yucca species. The yucca can be fertilized by no other insect, and the moth can use no other plant to raise its larvae.
Yucca
By courtesy of the New Mexico Department of Development