Sclerocactus brevispinus

Described as a new taxon (Sclerocactus wetlandicus var. ilseae) in 1993 and renamed as the distinct species Sclerocactus brevispinus in 1994. Not addressed under either name by Kartesz (1994), but accepted as S. brevispinus in Kartesz (1999). As treated by the U.S. Fish and Wildlife Service (USFWS), S. brevispinus material was considered to be included in the Listed Threatened Sclerocactus glaucus "complex" until 18 September 2007. On that date, USFWS "proposed to change the taxonomy of the Sclerocactus glaucus 'complex' to three distinct species: Sclerocactus brevispinus, S. glaucus, and S. wetlandicus" (USFWS 2007); on 15 September 2009, USFWS finalized this taxonomic change. Sclerocactus brevispinus is recognized as a distinct species by Heil and Porter in their treatment for the Flora of North America (2003); these authors state that "the combination of spheric stems, short spines, and small pink flowers make Sclerocactus brevispinus easily identified.... There is a well-documented cline of genetic mixing between Sclerocactus brevispinus and S. wetlandicus. An important natural threat to S. brevispinus is genetic swamping from the more widespread S. wetlandicus." Also recognized as a distinct species by the Utah Natural Heritage Program. Considered by Welsh et al. (1993) to be a minor variant within Sclerocactus whipplei var. roseus, but recognized as the distinct taxon Sclerocactus whipplei var. ilseae by Welsh et al. (2008).

Sclerocactus brevispinus is a small, barrel-shaped cactus of the western U.S.A. that is known from a single area a few miles across in the Pariette Draw region of the central Uinta Basin in Duchesne County, Utah. There are six occurrences documented with thousands of plants documented at different points in time. The range of this species requires study to better define it's boundaries. This species is highly threatened by the impacts from oil and gas development, trampling by livestock, genetic swamping from the more widespread Sclerocactus wetlandicus, and prolonged drought. Monitoring is needed to quantify the current population size and to document the species recovery after declines in 2016.

Sclerocactus brevispinus occurs in the western United States, where it is known only from a single area a few miles across in the Pariette Draw region of Duchesne County, Utah. Range extent was calculated using localities in the Utah Rare Plant Database (2021, UNHP 2021).

While there are many locations for this species, there are 6 when a 2 km separation distance is applied (UNHP 2021).

The biggest threat to this species is oil and gas development which fragments the habitat, compacts soil and increases sedimentation that makes it difficult for plants to go dormant underground, encourages the invasion of non-native species, and increases airborne dust that decreases plant photosynthesis potential as it settles on plants. On BLM and Ute Tribal lands, all of the species habitat is leased for oil and gas development or is part of a current project (USFWS 2010). The species is also threatened by horticultural collection, off-road vehicle use, pesticide application, predation (cactus-borer beetle (Moneilema semipunctatum), rodents, and lagomorphs), grazing and trampling by livestock, climate change (drought) grazing, and genetic swamping from the more widespread S. wetlandicus (FNA 2003, USFWS 2010).