Structure and identification
Plants form groups of spherical or ovoid stems. Tubercles are broad at the base, narrowing further out and upright, with a complete groove. Pale lateral spines vary in thickness, and upper ones sometimes gather in a bundle. The main central spine projects forwards and curves slightly downwards. The monograph describes golden-yellow flowers with a red throat, also noting forms with a greenish yellow throat. [Dicht and Lüthy 2005, p. 153–154]
Habitat and variation
The documented range includes Texas and parts of Tamaulipas, Coahuila and Nuevo León. The species occurs on alluvial plains and gentle ridges with limestone gravel. The authors describe local differences in armature size and thickness. C. sulcata is the type species of the genus, also identified in the 2022 revision. [Dicht and Lüthy 2005, p. 153–154; p. 145–146] [Sánchez et al. 2022, p. 153–154; p. 145–146]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Kaktologia 2009b, file p. 7] [Neciu b.d., file p. 1]
Synonyms and names in the literature
Cactus calcaratus · Cactus kotschubeyi · Cactus scolymoides var. sulcatus · Coryphantha calcarata · Coryphantha obscura · Coryphantha radians var. sulcata · Coryphantha roederiana · Coryphantha speciosa · Mammillaria calcarata · Mammillaria radians f. sulcata · Mammillaria radians var. sulcata · Mammillaria strobiliformis · Mammillaria sulcata [2-WWW]