Carex bajacalifornica Zika is described from five populations in the mountains of northern Baja California, Mexico, in the Sierra de Juárez and Sierra de San Pedro Mártir. It is distinguished from Carex rossii Boott by its short inflorescence bract, abbreviated perigynium beak shorter than the stipe, and nerved perigynium faces. Carex cryptosperma Zika, D.S. Bell, and L.J. Gross is described from 12 populations in southern California, in the San Bernardino, San Gabriel, and San Jacinto Mountains. Carex cryptosperma differs from Carex xerophila Janeway & Zika in its relatively short perigynium stipe and relatively long perigynium beak. The new species are illustrated and mapped, and a key is presented to members of Carex sect. Acrocystis in the states of California and Baja California.