Bull. S. Calif. Acad. Sci. 4: 15. 1905.
Shrubs, spreading to sprawling, forming large clumps, to 1 × 1–9 m. Stem segments not disarticulating, green, flattened, elliptic to obovate to rhombic, 15–25 (–40) × 6.5–14 cm, ± tuberculate, glabrous, usually glaucous; areoles 5–7 (–8) per diagonal row across midstem segment, prominent, subcircular (-oval), 4–6 × 4–5 mm, enlarging in age; wool gray. Spines 4–11 per areole, in most areoles, yellow with chalky white coat, to yellow with redbrown basal portions, aging reddish gray; erect ones terete, stout, straight; abaxial ones reflexed, shorter, to 12 mm; adaxial spines spreading, longest spines 20–40 mm. Glochids moderately dense in crescent at adaxial edge of areole, merging with subapical tuft when present, yellow to redbrown, to 5 mm. Flowers: inner tepals yellow to dull red throughout, 35–45 mm; filaments yellow to orange-yellow; anthers yellow; style pink to red; stigma lobes yellow-green to green. Fruits dark red-purple throughout, obovoid, 35–50 × 30–35 mm, juicy, glabrous, spineless; areoles 22–36. Seeds gray, subcircular, warped, 3–4.5 mm diam.; girdle protruding 0.5 mm. 2n = 66.
Phenology: Flowering spring (Apr–May).
Habitat: Coastal sage scrub, chaparral
Elevation: 10-400 m
Calif. (including Channel Islands), Mexico (Baja California)