''Trifolium friscanum'' is a rare species of flowering plant in the legume family known by the common name Frisco clover. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the US state of

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, where it is known only from

Beaver Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-large ...

and Millard Counties. It is found growing on the San Francisco Mountains, Beaver Lake Mountains, Wah Wah Mountains and Tunnel Springs Mountains. Most individuals live in the San Francisco Mountains, where the highest point is called Frisco Peak.Lanner, R. M. and R. Warnick. (1971)
Conifers of the San Francisco Mountains, San Rafael Swell, and Roan Plateau.
''Great Basin Naturalist'' 31:3 177. It was originally described as a

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

of '' Trifolium andersonii'' in 1978, but was elevated to species status in 1993.US Fish and Wildlife Service Species Assessment and Listing Priority Assignment Form.
USFWS. It occurs over away from the nearest ''T. andersonii''.
Trifolium friscanum.
' NatureServe. This is a low-growing dwarf plant with a taproot and woody stem. It is no more than tall. Each leaf is made up of three leaflets coated in silvery hairs. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

contains 4–9 reddish purple flowers. This plant grows in pinyon-juniper and

sagebrush Sagebrush is the common name of several woody and herbaceous species of plants in the genus ''Artemisia (plant), Artemisia''. The best-known sagebrush is the shrub ''Artemisia tridentata''. Sagebrush is native to the western half of North Amer ...

ecosystems. Other plants in the habitat include ''

Ephedra viridis ''Ephedra viridis'', known by the common names green Mormon tea, Brigham tea, green ephedra, and Indian tea, is a species of ''Ephedra (genus), Ephedra''. It is indigenous to the Western United States, where it is a member of varied scrub, woodlan ...

'' (Mormon tea), ''

Gutierrezia sarothrae ''Gutierrezia sarothrae'' is a species of flowering plant in the family Asteraceae known by the common names broom snakeweed, broomweed, snakeweed, and matchweed. It is a subshrub native to much of the western half of North America, from western ...

'' (snakeweed), '' Cercocarpus intricatus'' (dwarf mountain-mahogany), and '' Petradoria pumila'' (rock goldenrod). The local region is home to other rare plants, including '' Eriogonum soredium'' (Frisco buckwheat) and '' Lepidium ostleri'' (Ostler's peppergrass). Frisco clover is known as a "narrow endemic" because it grows on a particular substrate: gravelly and bouldery volcanic soils, Ordovician limestone, and dolomite. There are only five populations of this plant. The total population of the plant is not certain because it is difficult to count individuals of this mound-forming species. Also, some occur on private property where access is restricted.Tilley, D. 2012. tp://ftp-fc.sc.egov.usda.gov/ID/programs/plant/plant_guides/pg_frisco_clover.pdf Plant Guide for Frisco clover (''Trifolium friscanum'').USDA-Natural Resources Conservation Service, Aberdeen, ID Plant Materials Center. The main two threats to the species' survival are

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

and nonnative species. Mining has occurred in the region for a long time, as the substrates are rich in

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

, and

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

Gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

quarrying has also occurred. There are many old mine shafts in the area. Most mining has ceased now, but some local areas are vulnerable to continuing mining activity. Three of the five remaining populations of the plant are located at mining sites. Introduced plant species are also a threat to this species. The most notorious is '' Bromus tectorum'', cheatgrass. It grows in the area, and the aforementioned mining activity actually encourages its spread. Cheatgrass encourages fire in this area, which is not fire-adapted.

References

{{Taxonbar, from=Q7841527 friscanum Flora of Utah Plants described in 1978