The Mojave Desert is an arid rain-shadow desert and the driest desert in North America. It is in the Southwestern United States, primarily within southeastern California and southern Nevada, and it occupies 47,877 sq mi (124,000 km2). Small areas also extend into Utah and Arizona.
Its boundaries are generally noted by the presence of Joshua trees, which are native only to the Mojave Desert and are considered an indicator species, and it is believed to support an additional 1,750 to 2,000 species of plants. The central part of the desert is sparsely populated, while its peripheries support large communities such as Las Vegas, Barstow, Lancaster, Palmdale, Victorville, and St. George.
Yucca brevifolia is a plant species belonging to the genus Yucca. It is tree-like in habit, which is reflected in its common names: Joshua tree, yucca palm, tree yucca, and palm tree yucca.
This monocotyledonous tree is native to the arid southwestern United States, specifically California, Arizona, Utah, and Nevada, and to northwestern Mexico (Baja California, Baja California Sur, Sinaloa and Sonora).It is confined mostly to the Mojave Desert between 400 and 1,800 m (1,300 and 5,900 ft) elevation.
The Joshua Tree has barely any leaves, just a few balls on the edges.
According to en.wikipedia