Some 600 species of plants are known in the area. Common types in the valley floor include the Joshua tree, Mojave yucca, banana yucca, creosote, and blackbrush. Higher up the Utah juniper and Sonoran scrub oak (also called scrub live oak) come to dominate. Agave is easy to spot in red rock niches, with its thick low leaves and flowering stem that reaches twice the height of a man. The Calico Tanks trail has a plaque about prehistoric agave roasting pits. Ponderosa pines may be found at the top of the valley, where it connects to the Spring Mountains.