Monographs Details: Coryphantha missouriensis (Sweet) Britton & Rose
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - Stems solitary or in clumps, 5–10 cm; tubercles elongate, 12–15 mm; areoles very woolly; spines pubescent, at first yellowish, becoming dark gray; central spines 0–1(2), the radial ones 10–20, spreading, straight, 1–2 cm; fls 2.5 cm, yellow to yellowish-red; fr red, 1–2 cm; seeds black, 1 mm; 2n=44. Dry plains and hillsides, often among grasses; N.D. to Io., Mo., and Ark., w. to Mont. and Ariz. June, July. Ours is var. missouriensis. The var. caespitosa (Engelm.) L. D. Benson, with larger fls (ca 5 cm) and seeds (2.5 mm), may also be sought at our w. border.