these plants also tolerate the high concentrations of salt, while gypsophiles thrive in these conditions. The cane cholla and other cacti, as well as desert succulents like the soaptree yucca, are able to store water through the hot summers and dry winters, blooming in the spring. Desert grasses have developed a tolerance for the highly alkaline soil. Grass species like alkali sacaton and Indian rice grass provide food for many tiny animals, such as Apache pocket mice and kangaroo rats. Grass seeds produce a protein-rich kernel that dries well and fills many rodents' underground granaries. Native Americans used many parts of the soaptree yucca. The young flower stalks are rich in vitamin C, while the flower pods can be boiled or roasted. The leaf fibers were used for the fabrication of rope, matting, sandals, baskets, and coarse cloth. The roots were chopped and boiled to produce soap to wash hair, blankets, and rugs. Other plants include skunkbush sumac, Rio Grande cottonwood (Populus deltoides wislizeni), hoary rosemary mint, purple sand verbena (Abronia angustifolia), Mormon tea (also known as longleaf jointfir), and claret cup cactus whose fruit is among the sweetest of any desert plant. American Indians used the hoary rosemary mint for seasoning foods, and the purple sand verbena as a mild sedative. They used the skunkbush sumac's berries to make a tart drink, while the flexible stems were used for basketry and binding. The sumac's branches contain tannin, which is useful in producing dyes, and its leaves were used as an astringent to treat stings, bites, rashes, and sunburn. The cholla's fruit can be eaten raw or cooked, while its flower buds were used as a diuretic, and a hair tonic was made from its roots. Strips of the cottonwood's branches and bark were woven into baskets. The tree's buds and flowers are edible, and its bark was used for treating bruises, strains, and sprains. A tea made from cottonwood bark is an anti-inflammatory agent and mild diuretic. The Mormon tea plant contains traces of ephedrine, which is a stimulant and decongestant effective in countering symptoms of the common cold. Fauna More than 800 animal species inhabit the park, many of them nocturnal. Several species of animals have developed very specialized means of survival in this harsh environment, enabling them to thrive in a place with very little surface water and highly mineralized groundwater. Some species that inhabit the dunes