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 southwestern North America in the states of California, Arizona, Utah and Nevada, where it is confined mostly to the Mojave Desert between 400 and 1,800 meters (1,300 and 5,900 ft) elevation. It thrives in the open grasslands of Queen Valley and Lost Horse Valley in Joshua Tree National Park. A dense Joshua tree forest also exists in Mojave National Preserve, in the area of Cima Dome.
Two subspecies have been described: Yucca brevifolia ssp. jaegeriana (the Jaeger Joshua tree or Jaeger's Joshua tree or pygmae yucca) and Yucca brevifolia ssp. herbertii (Webber's yucca or Herbert Joshua tree), though both are sometimes treated as varieties or forms.