Stems unbranched (2-branched), green, depressed-spheric to short cylindric, 4-8.5 × 3-5.5 cm; ribs usually (12-)13(-14), not well developed, tubercles prominent on low ribs. Spines obscuring stems or nearly so; radial spines 6-8(-12) per areole, acicular, elliptic in cross section, 5-15 × 0.5-0.8 mm; central spines 4-5 per areole; abaxial central spines 1-2 per areole, white, gray, or purplish tinged, turned or curving somewhat downward, angled, strongly hooked, slightly contorted, terete to angled, 12-35 × 0.5-1 mm; lateral central spines 2 per areole, similar to abaxial but slightly shorter, usually not hooked; adaxial central spines 1-2 per areole, erect, recurved, white to tan, strongly flattened, conspicuous, 13-40 × 0.8-2 mm. Flowers funnelform to campanulate, 2.5-3 × 2-3 cm; outer tepals with brownish and yellowish margins, larger oblanceolate, 10-17 × 5-8 mm, apex mucronate, margins membranous, crisped or minutely toothed; inner tepals yellow, sometimes suffused with brown, largest tepals oblanceolate, 15-25 × 5-7 mm, apex mucronate; filaments white to greenish white; anthers yellow; styles minutely but densely papillate Fruits dehiscent along 2-4 vertical slits, green, turning red to tan, ovoid, 8-25 × 8-14(-22) mm, dry; scales few, membranous, scarious-margined, minutely toothed or fringed. Seeds black to light brown, 2.7-3 × 2.2-2.5 mm; testa with rounded papillae.
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