Marble Canyon cactus, Brady’s hedgehog cactus

Pediocactella bradyi (L. D. Benson) Doweld; Pediocactus simpsonii (Engelmann) Britton & Rose subsp. bradyi (L. D. Benson) Halda; Toumeya bradyi (L. D. Benson) W. Earle

Plants usually unbranched (rarely 2-12-branched). Stems subglo-bose to obovoid, 3.2-6.2 × 2.5-5 cm; areoles elliptic, lanulose. Spines smooth, relatively hard, spreading to recurved, somewhat pectinate, usually all radial (rarely with central spines); radial spines (7-)13-16(-18) per areole, tips bending downward, yellowish tan or white, 3-5 × 0.7 mm; central spines 0(-2) per areole, dark tan, rigid, straight or slightly curved, 3-4 mm. Flowers 1.5-2.2 × 1.5-3 cm; scales and outer tepals minutely toothed or denticulate or entire and undulate; outer tepals straw yellow with green or red-brown midstripes, 3-15 × 3-4.5 mm; inner tepals straw colored, 9-15 × 3-4.5 mm. Fruits green turning reddish brown, turbinate, 7-10 × 10 mm. Seeds brownish black, to 2.7 × 1.7-2 mm, papillate and rugose.

Flowering early spring. Great Basin desert scrub, clay soils of ledges often overlain with limestone gravel; of conservation concern; 1000-1200 m; Ariz.

Some authors have included Pediocactus winkleri and P. despainii as infraspecific taxa of P. bradyi. Chloroplast DNA sequence data strongly indicate a more distant relationship (see discussion under 8. P. winkleri).