The star cactus is now extremely rare in the wild, and only a few widely separated populations are known to persist today (2). This attractive and unusual cactus has been highly valued in the commercial cactus trade and over-collection has resulted in the local extinction of some populations. Despite protection, illegal collection continues to threaten the future of this species (4). Habitat destruction has been, and remains, the major cause of the decline in this species; vast areas have been converted to agriculture and road construction (5). In Texas, mechanical and chemical bush clearing techniques together with the introduction of invasive grasses have had devastating effects (5).