Trees or shrubs, intricately branched, 0.5-2 m. Stem segments firmly attached, green drying gray and ropelike, cylindric, 2-8(-10) × 0.4-1 cm; tubercles rhombic, convex (flattened upon drying), 0.4-0.8 cm; areoles subcircular abaxially, adaxially becoming usually deltate-linear; glochid-bearing portion protruding distally, wedged between bases of 2 adjacent tubercles, (3-)4-7 × 1-1.5(-2) mm; wool tan to white. Spines 0-5 per areole, usually in distal areoles or sometimes absent or nearly so, tan to red-brown to deep purple, aging gray; major abaxial spines 0-1(-2), the longest spine spreading, (1.5-)2.5-6 cm; adaxial spines usually reflexed, short to ± 1 cm; sheaths baggy. Glochids in subcircular to linear adaxial tuft, yellow to tan to brown, to 2 mm. Flowers: inner tepals bronze-red ± suffused rose, with mid stripes darker, ovate, 6-13 mm, acute-apiculate to attenuate; filaments greenish; anthers yellow; style whitish or blushed with rose-pink or light green; stigma lobes whitish. Fruits maturing tan, ellipsoid to stipitate-ellipsoid, 15-30 × 10-15 mm, dry at maturity, tuberculate, developing increasingly burlike, with many bristlelike spines; areoles (32-)40-66, evenly spaced, woolly. Seeds pale yellow to tan-gray, angular to squarish in outline, warped, 4-4.5 × 3.5-4 mm, sides irregularly concave-convex; girdle smooth. 2n = 22, 44. Flowering spring-summer (Apr-Aug). Mojave and Sonoran deserts, washes, flats, and bajadas, sandy loam, desert pavement, stony volcanic substrates; 50-1100 m; Ariz., Calif., Nev.; Mexico (Baja California, Sonora).
Plant: Tree or shrub, intricately branched, 0.5-2 m tall; STEM segments firmly attached, cylindric, green drying gray and rope-like, 2-8(-10) cm long, 0.4--1 cm in diam.; tubercles rhombic, convex (flat upon drying), 4-8 mm long. AREOLES tan- to white-felty, subcircular in basal areoles becoming mostly deltoid-linear in distal areoles, (3-)4-7 mm long, 1-1.5 mm wide, the apical glochid-bearing portion protruding distally and wedged between the bases of 2 adjacent tubercles Leaves: SPINES mostly in distal areoles or sometimes absent or nearly so, tan to red-brown to deep purple, aging gray, 0-5 per areole, baggy-sheathed; major apical spines 0-1(-2), the largest one spreading, (1.5-)2.5-6 cm long; basal spines mostly reflexed, short to ca. 1 cm. GLOCHIDS in a subcircular to linear apical tuft, yellow to tan to brown, to 2 mm in diameter Flowers: inner tepals bronze-red commonly suffused with rose with midstripes darker, ovate, acute-apiculate to attenuate, 6-13 mm long; filaments greenish, the anthers yellow; style whitish or blushed with rose-pink or light green; stigmas whitish Fruit: maturing tan, dry, developing increasingly bur-like, with evenly spaced woolly areoles producing many bristle-spines, ellipsoid to stipitate-ellipsoid, 1.5-3 cm long, 1-1.5 cm in diam.; areoles (32-)40-66. SEEDS 4-4.5 mm long, 3-5.4 mm wide, pale yellow to tan-gray, angular to squarish in outline, warped, the sides irregularly concave-convex, the girdle smooth Misc: Sandy loam, desert pavement to stony volcanic substrates, on washes, flats and bajadas; 50-1050 m (200-3400 ft); Apr-Aug REFERENCES: Pinkava, Donald J. 1999. Cactaceae. Ariz. – Nev. Acad. Sci. 32(1).