Washington County's Endangered Plants

Arctomecon humilis
Dwarf (or Low) bearclaw poppy
Federally listed species since 1979
Lives only in Washington County, Utah
Poppy family

Primary threats: Urban expansion (residential and commercial development, highway projects completed and proposed leading to direct habitat loss, loss of pollinators and habitat fragmentation) and off road vehicles
Recent/impending impacts: Sun River expansion destroyed plants/habitat in May 2004, Atkinville interchange, Southern Corridor, further Sun River expansion, SITLA actions on White Dome and particularly the road that SITLA plans to build directly through its habitat destroying more plants and fragmenting its habitat further, massive residential development in or near almost of its remaining range, significant ongoing damage by OHV's
Learn more about the conservation history of this species
Arctomecon humilis juvenile 4/27/02 Warner Tony Frates
Arctomecon humilis juvenile
Arctomecon humilis 4/27/02 Atkinville Tony Frates
Arctomecon humilis
Arctomecon humilis juvenile 4/27/02 Warner Tony Frates
Astragalus ampullarioides
Shivwits (or Shem) milkvetch
Federally listed species since 2001
Lives only in Washington County, Utah
Pea family

Primary threats: Urban expansion (see above) and invasive species
Astragalus ampullarioides 5/2/04 Tony Frates
Astragalus ampullarioides

Astragalus holmgreniorum
Holmgren's (or Paradox) milkvetch
Federally listed species since 2001
Lives primarily in Washington County, Utah
(a few plants occur just barely over the UT-AZ border)
Pea family

Primary threats: Urban expansion (see above), off road vehicles and invasive species
Impending impacts: Atkinville interchange, Southern Corridor, Sun River expansion, massive residential and other development planned by SITLA in its largest extant population
This plant species may currently be the most endangered of becoming extinct in Utah.
Astragalus holmgreniorum 5/2/04 Tony Frates
Astragalus holmgreniorum

Pediocactus sileri
Siler (or Gypsum) cactus
Federally listed species since 1979 (reclassified in 1993)
Lives only in Washington and Kane Cos. in Utah
(also occurs in northwestern Arizona)
Cactus family

Primary threats: Urban expansion, off road vehicle use, cattle grazing, cactus poaching and gypsum mining
Impending impacts: Southern Corridor, SITLA actions on White Dome, motorcyle/ATV events

Very slow growing and very prone to impacts; juvenile plants seem to be missing in a number of populations. These plants and the biologic crusts upon which they depend need to be left undisturbed.

Pediocactus sileri 5/3/04 Tony Frates
Pediocactus sileri
Pediocactus sileri 4/27/02 Tony Frates
Petalonyx parryi
Parry's petalonyx
Rare plant species (shrub)
In Utah, only lives in Washington County
(also occurs in Nevada and Arizona)
Blazing star (or Stickleaf) family

Primary threats: Urban expansion (the plant pictured to right/top was destroyed by residential development shortly after being photographed in 2004); gypsum mining
Recent/impending impacts: Silver Falls/KLC Properties residential development resulted in the destruction of plants/habitat in May 2004 and other residential development near the town of Washington (Washington Fields); Southern Corridor, SITLA actions on White Dome

This plant requires gypsipherous soil. An historic St. George population from which it was first collected by Dr. Charles C. Parry no longer exists.

A related species, Petalonyx nitidus has not been collected in Utah since the 1930's (Washington County's Santa Clara area) and probably no longer exists in Utah. It is smaller in stature than P. parryi.

Petalonyx parryi 5/3/04 Tony Frates
Petalonyx parryi
Petalonyx parryi 5/2/04 Tony Frates
Sphaeralcea gierischii
Gierisch's globemallow
Federal candidate species as of Dec. 10, 2008
In Utah, occurs only at extreme southern edge of Washington County
Only one population occurs in Utah
Also occurs in adjacent Mohave County, Arizona
Mallow family

Primary threats: Gypsum mining, off road vehicles and other recreational impacts
Recent/impending impacts:The growth of Sun River, the new St. George airport and ever increasing local human populations place the lone Utah occurrence at ever increasing peril.

All Utah-Arizona occurences occur within roughly a 10 square mile area; total occupied habitat is less than 60 acres.

Sphaeralcea gierischii Washingon County, Utah 4/30/05 by Tony Frates
Sphaeralcea gierischii