Bryophytes, the first plants to grow on land, include three distinct lineages: mosses, liverworts, and hornworts. These non-vascular plants lack roots, flowers, seeds, and a defined system of tissues for transporting fluids. They reproduce by single-celled spores or form new plants by vegetative means. Lacking roots, bryophytes are not restricted to growing in soil; many bryophytes are quite content to grow on rock surfaces.
Starting in 2011, John Brinda and Lloyd Stark of University of Nevada Las Vegas have been leading an effort to inventory Joshua Tree National Park's bryophyte diversity. To date, Dr. Brinda has made 312 collections from over 30 sites in the park. He has documented 50 different species of mosses (representing 12 families and 28 genera) and four species of liverworts, one of which is considered new for California.