Dwarf Bear-poppy

Arctomecon humilis

Description

Dwarf bear-poppy, also commonly known as Colville bearclaw poppy, grows as a compact clump of stems, with deeply toothed, leathery leaves gathered at the base of the plant. The hairy leaves are topped by multiple nodding buds, each on a separate stem. Papery four-petaled, white flowers become erect when blooming and seem to float above the clustered leaves of the plant.

Habitat

The species grows in outcrops of the Moenkopi Formation in gypsum-rich soil. This transitional area, known as the Dixie Corridor, is where vegetation endemic to the Mohave Desert is found growing on sedimentary strata of the Colorado Plateau.

The Dixie Corridor is a badlands environment with both alkaline and nonalkaline soils. These two soil types form hard surface crusts that impede seedling emergence. The dwarf bear-poppy favors three geological strata of the Moenkopi Formation: the upper red, the Shnabkaib or white gypsiferous, and the middle red just below ridges and buttes. The elevation of population sites ranges from 2,700 to 3,300 ft (825-1,005 m).

Distribution

The dwarf bear-poppy is endemic to the gypsum-rich soils of the Mohave Desert-Colorado Plateau area of Washington County, Utah. Both of the populations found in the late nineteenth century at St. George, and near Bloomington, Utah, have been lost. The construction of Interstate Highway 15 may have destroyed additional populations.

The two other members of its genus (Arctomecon californica and A. merriamii ) are separated from the range of the dwarf bear-poppy by more than 50 mi (80.5 km) and two mountain ranges.

Dwarf bear-poppy is currently found only in the southwestern corner of Washington County, Utah, within 7 mi (11 km) of St. George, Utah. Large plant populations occur at the base of Red Bluff west of Bloomington and at the north base of Santa Clara Butte. Healthy populations of up to 25 plants per acre occur at the base of Warner Ridge. Numerous other sites support small numbers of individuals.

Threats

The limited biogeographic range of dwarf bear-poppy has been further reduced by land development. Construction and mining near St. George could lead to the destruction of additional populations. Mineral exploration and the recreational use of off-road vehicles have taken a toll on the species. The building of the town of Bloomington, Utah, destroyed about a third of the known population.

A continuing threat to the dwarf bear-poppy is the possible strip-mining of gypsum deposits that lie near the surface throughout the region. Although mining is not currently economically profitable, annual assessment of the many existing claims results in considerable habitat damage. Although the plant does not transplant well, collectors have vandalized populations for home gardens and the commercial trade.

Conservation and Recovery

Large blocks of state land around St. George and Bloomington support more than half the known plants. The Bureau of Land Management controls the Warner Ridge site and several smaller sites. Santa Clara Butte, Boomer Hill, and White Hills populations are the most remote and undisturbed. Of these, the Santa Clara Butte population is the largest, consisting of 400 plants.

The U. S. Fish and Wildlife Service Recovery Plan for the species calls for closing dwarf bear-poppy habitat areas to year-round off-road vehicle use and closer supervision of mining activities. It also recommends detailed surveys of Utah sites as well as surveys of possible habitat areas in neighboring Arizona where dwarf bear-poppy is believed to have once grown.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
P.O. Box 25486
Denver Federal Center
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Atwood, N. D. 1977. "The Dwarf Bear Poppy." Mentzelia (Journal of the Northern Nevada Native Plant Society) 3:6-7.

Janish, J. R. 1977. "Nevada's Vanishing Bear Poppies." Mentzelia 3:2-5.

U.S. Fish and Wildlife Service. 1985. "Dwarf Bear Poppy Recovery Plan." U.S. Fish and Wildlife Service, Denver.