Big Galleta is a species of clumping perennial grass that is widespread in California deserts. The clumps help stabilize sand dunes. According to botanist Philip A. Munz, "it is said to be one of the most valuable forage grasses of the desert". Clumps can live more than 100 years.
Big galleta is found in sand dunes, bajadas, scrublands, woodlands, and deserts. It prefers dry, open, sandy to rocky slopes and flats. It occurs on all soil types but has poor growth in clay soils. It is tolerant of arid environments such as desert floors, and it is the dominant grass in some desert scrub regions. It acts as a nurse plant to seedlings of other species, such as cholla and barrel cactus, in turn receiving protection by growing next to the spiny plants.