Astrophytum capricorne var crassispinum
Origin and Habitat: Cuatro Cienegas, Mexico.
Description: Astrophytum capricorne var crassispinum is very similar to Astrophytum capricorne v. niveum (and the differences between this variety is questionable). A. capricorne var. crassispinum is characterized by a sharp-ribbed body, the ribs are the same as Astrophytum capricorne, but the stem is larger bright green and almost bare (lacks white dots).
Spines: The 6-8 spines are striking strong and up to 8.5 cm long, flat, black to brown in the youth, later grey-chalky. They are noticeably stronger, larger and thicker than in the common Astrophytum capricorne. Yellow spined plant are also common in cultivation.
Flowers: The blossoms have a reddish eye as in Astrophytum capricorne var. niveum but pure sulphurous flowers are also mentioned .