Echinocactus polycephalus var. polycephalus
Stems gray-green. Spines red to gray, infrequently straw colored, canescent. Fruit scales reddish to maroon, aging tan or black, 10–14 mm, usually shorter than dried tepals at fruit apex, spine tips canescent with strap-shaped, unicellular trichomes. Seeds rounded or faceted with flat planes transversing testa, 2.8–4.7 mm, papillate-roughened (exposed surfaces of testa cells protruding, hemispheric to hexagonally faceted, appearing dull except for microscopically sparkling individual facets). 2n = 22.
Phenology: Flowering Jul–Aug.
Habitat: Rocky flats and washes, bajadas, rock ledges, Mojave and Sonoran desert scrub, igneous and calcareous substrates
Elevation: [10-]30-1700 m
Ariz., Calif., Nev., Mexico (Sonora)