''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 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 found elsew ...

to the US state of

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

, where it is known only from

Beaver Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers ar ...

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 The San Francisco Peaks (Navajo: , es, Sierra de San Francisco, Hopi: ''Nuva'tukya'ovi'', Western Apache: ''Dził Tso'', Keres: ''Tsii Bina'', Southern Paiute: ''Nuvaxatuh'', Havasupai-Hualapai: ''Hvehasahpatch''/''Huassapatch''/''Wik'hanbaja' ...

, 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 An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

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''. The best known sagebrush is the shrub ''Artemisia tridentata''. Sagebrushes are native to the North American west. Following is an alph ...

ecosystems. Other plants in the habitat include ''

Ephedra viridis ''Ephedra viridis'', known by the common names green Mormon tea, green ephedra, and Indian tea, is a species of ''Ephedra''. It is indigenous to the Western United States The Western United States (also called the American West, the Far West, ...

'' (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 ''Cercocarpus ledifolius'' var. ''intricatus'' (little-leaf mountain mahogany, narrowleaf mahogany,Canyon Country Wildflowers, Damian Fagan, 2nd ed., 2012, Morris Bush Publishing, LLC. in cooperation with Canyonlands Natural History Association, ...

'' (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 The soil composition of vineyards is one of the most important viticultural considerations when planting grape vines. The soil supports the root structure of the vine and influences the drainage levels and amount of minerals and nutrients that the ...

, Ordovician limestone, and

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

. 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 extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

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 with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...

zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc 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 periodi ...

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

, and

copper Copper is a chemical element with the symbol Cu (from la, cuprum) 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 pinkis ...

Gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

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 ''Bromus tectorum'', known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, southe ...

'', 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