Structure and identification
The stem is solitary, hemispherical or short-cylindrical, with a grey-blue-green epidermis. Very broad tubercles have a flattened upper side and a deep groove containing yellow-orange glands. Lateral spines are strong, lower ones partly flattened, and the dominant central spine straight. Flowers are large and broadly funnel-shaped. Young plants have much flatter tubercles, and complete grooves develop later. [Dicht and Lüthy 2005, p. 46–47]
Habitat and variation
The monograph documents sites in Coahuila, San Luis Potosí, Durango and Zacatecas, on sparsely vegetated alluvial plains with sandy-gypsum or gravelly soil. A later study of morphology and microsatellites confirmed the clear distinctness of this group from C. robustispina, despite partial overlap in the values of individual traits. [Dicht and Lüthy 2005, p. 46–47; p. 985, 994–996] [Baker and Butterworth 2013, p. 46–47; p. 985, 994–996]
Comparison with Coryphantha robustispina
In Baker and colleagues' 2013 analysis, C. poselgeriana formed a group distinct from C. robustispina in both morphology and the ISSR DNA markers used. The study compared differences between these two species with geographical variation within C. robustispina. Stronger species separation accompanied considerable overlap in traits among the traditional subspecies of C. robustispina. [Baker and Butterworth 2013, p. 989–996]
Related articles
Synonyms and names in the literature
Cactus salm-dyckianus · Coryphantha kieferiana · Coryphantha poselgeriana var. valida · Coryphantha salm-dyckiana · Coryphantha valida · Echinocactus poselgerianus · Echinocactus salm-dyckianus · Mammillaria kieferiana · Mammillaria salm-dyckiana [2-WWW]