Stems 0-3-branched, green to dark green, ovoid or cylindric (sometimes narrowly so), 3-15 × 2-8 cm; ribs (6-)13(-14), tubercles prominent on ribs. Spines dense but not obscuring stems; radial spines 6-12(-16) per areole, spreading, white, 3-18 × 0.3-1.2 mm, pubescent; central spines (1-)3-6(-7) per areole, terete to angled, pubescent in young and early reproductive plants; abaxial central spines 1-3 per areole, tan to brown, reddish, or black, irregularly- or strongly-hooked, 20-55 mm; lateral spines (0-)2(-4) per areole, white, tan, red, or reddish brown, usually hooked, sometimes flattened and ribbonlike, 10-40 mm; adaxial spine 1 per areole, tipped white or dark, flattened and ribbonlike, (5-)35-60(-70) × 1.5-2.5(-3.5) mm. Flowers funnelform to campanulate, 2-4 × 1.5-3 cm; outer tepals with reddish brown midstripes and violet-pink or reddish purple margins, usually oblanceolate, 15-20 × 6-10 mm, margins irregularly toothed, apex mucronate; inner tepals lavender to reddish purple, oblanceolate to narrowly oblanceolate, 15-20 × 4-6 mm, apex minutely toothed; filaments red-violet or pink; anthers yellow; styles minutely and sparsely papillate. Fruits dehiscent along 2-4 vertical slits, green to pink or pale red, barrel-shaped, 9-15 × 8-13 mm, dry; scales few, membranous, slightly scarious-margined. Seeds black, 2-2.5 × 3-4 mm; testa with rounded papillae. Flowering late Apr-May. Igneous or calcareous gravels, galleta grasslands, greasewood, sagebrush, or shadscale flats; of conservation concern; 1500-1800 m; Nev., Utah. Sclerocactus blainei is an unusual species of Sclerocactus, sometimes possessing long ribbonlike spines reminiscent of S. papyracanthus. Sclerocactus blainei differs from other sclerocacti in its range (e.g., S. pubispinus and S. spinosior) in that the flowers are slightly larger and the adaxial central spine is longer than either S. pubispinus or S. spinosior. The central spine number varies, and the number of hooked spines may be as many as six, which is characteristic of S. polyancistrus.