From the Digest

Cacti, Succulents and the Endangered Species Act

By Joe Merkelbach (October 2008)

Most of the attention to species that are threatened or endangered is directed towards animals and birds, but plants are also included on the list. The U.S. Fish and Wildlife Service, which administers the Endangered Species List, lists 747 different plants as threatened or endangered, almost all with populations within the United States. The largest group, as would be expected, are endemic species from the Hawaiian Islands.

Although cacti are well protected by spines, they do not run well and so are subject to various threats. Most of the ESA-listed species are quite small and in many cases cryptic, but they are usually confined to small areas of specialized habitat that can be disrupted.

Collection from the wild has historically been a problem, but increased environmental concern by both collectors and the public has lessened its consequences. Development for housing and roads, and land changes due to grazing use are still factors affecting species constrained to small habitats. A newer threat is the unrestrained use of all-terrain vehicles driven over critical habitat areas. The current biggest concern, just as with animals, is protection of the habitats in which the plants thrive; without an undisturbed place to live, the species cannot survive.

There are 13 genera of cacti on the U.S. official plant list of endangered and threatened species. They comprise a group of 28 different species and subspecies. Almost all are from areas of the Southwest – the Chihuahuan, Sonoran and Great Basin Deserts – but one, Leptocereus graniatus, is from Puerto Rico, and another, Pilosocereus robinii, comes from the Florida Keys. There is even one opuntia species on the list, the Bakersfield cactus, Opuntia treleasei.

The Desert Botanical Garden in Phoenix is the location of the southwest regional desert area collection of the Center for Plant Conservation. This is a set of plants considered worthy of special conservation in the area. Thirty-six species are included, with some agaves as well as cacti.

The concern for endangered species has helped fund research, which has benefited some of our favorite types of plants in the wild. Education and consequent habitation preservation will help cacti and succulents maintain their presence in nature.

The website for the Desert Botanical Garden is Choose the research tab to find out more about the Center for Plant Conservation collection.