Siler Pincushion Cactus
Pediocactus sileri
Other common names: Gypsum Cactus
NatureServe conservation status
Global (G-rank): G2G3
State (S-rank): S2
Utah Wildlife Action Plan status
- SGCN
External links
General information
Pediocactus sileri is a Federally listed as threatened species that occurs in a narrow region along the Arizona-Utah border in Kane and Washington counties, Utah, and adjacent Coconino and Mohave counties, Arizona. This rare species is found on gypsum-rich clay and sandy soils. Siler's Pincusion Cactus has yellow flowers with long fringed edges and has both central and radial spines which make it a beautiful but dangerous plant to encounter in the desert of Southwest Utah.
This plant shares its unique habitat with another Federally listed endangered species, Arctomecon humilis (Dwarf Bearclaw Poppy). This ecological community has received press in recent years as it is under threat from housing developments in the Saint George area.
Description
Pediocactus sileri is a Federally listed as threatened species that occurs in a narrow region along the Arizona-Utah border in Kane and Washington counties, Utah, and adjacent Coconino and Mohave counties, Arizona. This rare species is found on gypsum-rich clay and sandy soils. Siler's Pincusion Cactus has yellow flowers with long fringed edges and has both central and radial spines which make it a beautiful but dangerous plant to encounter in the desert of Southwest Utah.
This plant shares its unique habitat with another Federally listed endangered species, Arctomecon humilis (Dwarf Bearclaw Poppy). This ecological community has received press in recent years as it is under threat from housing developments in the Saint George area.
Phenology
Flowers from March to April (sometimes May)
Diagnostic characteristics
Pediocactus sileri is unlikely to be mistaken for any other cactus in Washington County - it is the only Pediocactus species yet recorded in Washington County, and it is restricted to gypsum-rich soils where other cactus species are unlikely to occur.
Species range
Scattered areas along the Utah-Arizona border from the vicinity of Fredonia, Coconino County, Arizona, to an area south and southeast of St. George, Utah in Mohave County, Arizona and at a few places in Washington County, Utah.
Threats or limiting factors
The primary threats to this species are most likely drought and natural predation. Threats may also include recdreation and grazing, but the extent of these threats are unknown (USFWS, 2018). Finally, threats from urban development in the St. George area are likely impacting this species, although it is unclear to what extent development will impact the species.
Taxonomy
No, this species does not have taxonomic discrepancies