Coryphantha cornifera

Coryphantha cornifera typically but not always grows alone. Its stems range in shape from globose to cylindrical, and its general color is a dull olive-green. The cacti measure 6 to 12 cm (2 to 5 in) tall and 8 to 15 cm (3 to 6 in) in diameter, and have fibrous or semi-fibrous roots. The cactus's top, at least on older plants, is blunt, depressed, and maybe be covered with white wool. The cactus's surface is divided into numerous tubercles looking like the bottoms of green chili peppers. Atop each tubercle spines arise from special areas called areoles; this species' areoles typically produce 12–18 radiating spines, and often 1–4 longer and more robust central spines; spine arrangement is highly variable.

Coryphantha cornifera inhabits semi-arid scrub and grasslands, and occasionally disturbed areas oak forests. The species shows a preference for limestone in flat or gently sloping areas. It inhabits elevations of 1,400–2,200 meters (4600–7200 feet). It flowers from June to July, sometimes extending into September.

The generic name Coryphantha derives from the Greek coryphe, meaning "top" or "head", and anthos meaning "flower"; the whole genus name refers to the flowers appearing atop the stems. The species name "cornifera" is derived from the Latin words cornus, meaning "horn") and fer meaning "bearing"; this refers to the usually present, larger and more robust central spine or spines of the species, which may be shaped like a horn or hook.