Astrophytum capricorne v. niveum near Cuatro Cienegas, Coahuila
Among the most impressive landscapes of the Chihuahuan Desert, in addition to the stone steppes, are the closed basin geological formations. They are formed by mountain ranges that surround often vast plains and valleys, so that a natural drainage is not possible. In Mexico they are therefore called characteristic "bolson", which means pocket or bag. Especially famous for this is the Bolson de Cuatro Cienegas in northern Coahuila. It covers an area of approximately 500 square kilometers and is surrounded by the mountains of the Sierra Anteojo, Ovejas, Purisima, San Marcos and La Fragua. The site is located at about 780 m above sea level.
On the foot hills of the Sierra Anteojo near Cuatro Cienegas Astrophytum niveum v. capricorne often grows unprotected in the rough, chalky gray gravel or occasionally under dry bushes. On the western Bolson exit it grows in habitats up to 1100 m above sea level under more dense, ground-covering vegetation between calcareous plates and accompanying rock crashes. In contrast to the copies at the foot hills you can find variable plant spines of extremely coarse to fine and surprisingly thin.
Agave lechuguilla, Ariocarpus fissuratus, Echinocactus horizonthalonius, Echinocereus pectinatus, Echinocereus stramineus, Epithelantha micromeris, Escobaria zilziana, Euphorbia antisyphilitica, Ferocactus hamatacanthus, Fouquieria splendens, Larrea tridentata, Lophophora williamsii, Mammillaria pottsii, Opuntia bradtiana, Opuntia imbricata, Prosopis juliflora, Sclerocactus mariposensis, Sclerocactus uncinatus, Selaginella lepidophylla, Yucca rigida, Yucca thompsoniana.
Astrophytum capricorne v. niveum