Joshua tree in the context of Mohave County, Arizona

Yucca (/ˈjʌkə/ YUCK-uh) is both the scientific name and common name for a genus native to North America from Panama to southern Canada. It contains 50 accepted species. In addition to yucca, they are also known as Adam's needle or Spanish-bayonet. The genus is generally classified in the asparagus family in a subfamily with the Agave, though historically it was part of the lily family. The species range from small shrubby plants to tree-like giants, such as the Joshua tree. All yuccas have rosettes of leaves that taper to points and inflorescences with many flowers that are mainly cream white with thick petals. Though adapted to a wide range of climates the plants are xerophytes, ones that specialize in dry living conditions.

The tight relationship between the yucca plants and their pollinators, the yucca moths from the genera Tegeticula and Parategeticula, is a well known example of evolutionary mutualism. They are an important part of the ecology of North American deserts, providing shelter to small animals and creating habitats. The human uses of yuccas include garden plants, as food, and for extracts. The flower petals of various species are eaten as a part of local cuisine, particularly in Central America and Mexico. Historically, the yucca was extensively used for its fibers to make cords, baskets, mats, and sandals. It continues to be used by native peoples for traditional soaps.

Lost Horse Valley is a valley in Joshua Tree National Park. It has been called "the centerpiece of the park" because of the quality of its stands of Joshua trees and its geological formations. It contains the Lost Horse Mine, of significant historic importance in the park.