Cacti in Danger: The Perils of the San Rafael Cactus

San Rafael Cactus

Pediocactus Despainii

By Ray McDonnell-Horita

Pediocactus despainii (San Rafael Cactus). Dennis Udink. 2014

Description and Ecology:

The San Rafael Cactus, or Pediocactus Despainii is one of the many endangered plants on the endangered species list. This small, subglobose to ovoid, leafless, stem succulent flowers at the upper end of its tubercles near the top of the stem. This beautiful and interesting cacti is in danger mainly because of human actions which need to be changed in order to save the San Rafael cactus. 

Geographic and Population Changes:

San Rafael Swell

This plant is located in Emery County, Utah and has three populations with approximately 20,000 individual cacti. The three populations are restricted to the Northern area of the San Rafael river, and South/West of Highway 70. Most of these areas are part of lands managed by the Bureau of Land Management. The cacti thrives in fine textured, mildly alkaline soils rich in calcium derived from the surrounding limestone substrates. They generally grow on benches, hill tops, slopes, and sites with south exposure. Due to its highly restricted populations, this cacti is extremely vulnerable and was thus added to the endangered species list on September 18th 1987. The exact historical ranges of the cacti are unknown, yet there has been a disadvantageous human impact on its habitat. 

Listing Date and Type of Listing:

The San Rafael cactus was discovered by Kim Despain in 1978 on the San Rafael swell in Emery County, Utah. It was then added to the endangered species list on September 18th 1987. Due to the late discovery of this cacti, the long-term population dynamics are unknown. Therefore, the recovery plan needs more data in order to determine the most effective steps. 

Threats to Continued Existence:

Off roading vehicle in the San Rafael Swell

Major threats to the continued existence of the San Rafael cactus mainly involve the actions of humans. Due to the small and restricted nature of the cacti, human-caused habitat destruction is a major issue for these plants. These cacti are rare, and highly desired among collectors and gardeners. Due to the scattered population of these cacti, it is difficult to monitor and protect this species from unauthorized collecting. This collecting by cacti enthusiests is a major threat to this species. Another danger to the San Rafael cacti is the popular recreational activity of off roading. These large off roading vehicles trample the delicate cacti and destroy their habitat. Although livestock trampling is also an issue to these cacti, off roading is much more detrimental and destructive to the habitat. Lastly, the annual development and work on mineral claims for gypsum, uranium, bentonite clay, petroleum, and other minerals is also destructive to the habitat of this species. 

Description of Recovery Plan:

The two main goals of the recovery plan for the San Rafael cactus are: to maintain viable population of the San Rafael cactus, and to initiate conservation and recovery measures which may lead to the downlisting of the cacti to threatened. These two goals are to be achieved by completing the following tasks:

1. Prevent collecting and destruction of the San Rafael cactus from wild populations

2. Control activities which affect the habitat of the San Rafael cactus through laws and regulations

3. Inventory suitable habitat for each species and determine their population and distribution

4. Establish and conduct monitoring, biological, ecological, life history and minimum viable population study for each species

5. Establish and implement formal land management designations which would provide for habitat protection for the San Rafael cactus

6. Propagate individuals of San Rafael cacti in horticultural facilities

7. Develop  public awareness, appreciation and support for the conservation of the San Rafael Cactus 

Map of the San Rafael Swell

Works Cited:

U.S. Fish and Wildlife Service. 1995. Utah pediocactus: San Rafael Cactus (Pediocactus despainii) and Winkler cactus (Pediocactus winkleri) recovery plan. Denver, Colorado. 28 pp.