Widely distributed in the Mexican parts of the Chihuahuan Desert, Thelocactus bicolor‘s range elsewhere is restricted to two counties in adjacent Texas, Brewster and Starr.
Much like yesterday’s Alaska blue-eyed grass which is primarily found in another region (British Columbia), this species has a common name of “glory of Texas” or Texas pride. It has long been in cultivation, as evidenced by discussion in this 1843 work: Abbildung und Beschreibung blühender Cacteen; figures des cactées en fleur, peintes et lithographiées d’après nature avec un texte explicatif, par Louis Pfeiffer et Fr. Otto. (text (as Echinocactus bicolor), illustration). Unfortunately, as today’s photographer notes: “[it is] Infrequent even in its preferred habitat, it has been made even rarer by unscrupulous cactus thieves who sell them to collectors who prize them highly.”.
As one might expect in a Texas dryland, Thelocactus bicolor grows in “xerophyllous scrub on gravelly soils of hills and alluvial fans in desert or grassland”.