Involucral bracts acute. Fruits light brown, with 10 slender, tan, longitudinal ribs alternating with 10 brown, often interrupted ribs, fruit surface smooth, not mucilaginous when wetted. Flowering spring-summer. Gravelly and sandy soils, oak woodlands, pinyon-juniper woodlands, chaparral, sagebrush scrub, creosotebush scrub, shadscale scrub; 50-2100 m; Ariz., Calif., Nev., Utah; Mexico (Baja California).