Cleistocactus strausii
The cactus prefers free draining soils, strong sunlight, but not high temperatures — in fact it can withstand hard frosts down to -10 °C. In its natural habitat it receives plenty of water during the summer, but almost none over the winter. In cultivation, watering too much in winter often leads to root rot.
Echinomastus mariposensis
Threats to this rare species have included mercury mining, petroleum exploration activities, off-road vehicles, and grazing. The worst threat has been poaching by cactus collectors. The collectors employed professional diggers to go into the habitat and retrieve this and other species of cacti, which were stockpiled, shipped away for sale, and sometimes discarded or wasted. The type locality of the cactus has been scoured for specimens and few are found there anymore. Plants in Big Bend National Park occur on rugged terrain and have generally been safe from collectors. In 1983 the cactus was placed on Appendix 1 of CITES in an effort to protect it from harvesting.