This small, rather inconspicuous but locally common cactus is characterized by elongated tubercles that point upwards and have between 2 and 8 differently-angled central spines, brown in color, surrounded by 9 to 15 shorter, white, radial spines, but the green stems are still clearly visible. Coryphantha macromeris
prefers shady positions, beneath larger plants or partly covered by grass. Stems are small, not exceeding 6 inches in height, are solitary for several years then start to cluster. The runyonii variety of south Texas has shorter spines and forms large clumps of small stems. Purple flowers bloom in late summer, followed by green fruits.