''Achyronychia'' is a monotypic genus of flowering plant containing the single species ''Achyronychia cooperi'', which is known by the common names onyxflower and frost-mat. This plant is native to the Mojave and

Sonoran Desert The Sonoran Desert () is a hot desert and ecoregion in North America that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the Southwestern United States (in Arizona and California). It ...

s of northern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

s of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

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 ...

and

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

. In California, it is known from

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

, Imperial, Riverside,

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

, San Bernardino and Inyo Counties. In Arizona, it occurs in Yuma, Mohave, Pima, Pinal and Maricopa Counties. It has also been reported from Washington County in Utah, and from Clark County, Nevada. Onyxflower is a diminutive plant which lies in a small mat flat on the ground. Its habitat is sand. It radiates several prostrate stems in all directions, each only a few centimeters long. The thick pale green leaves are paddle-shaped and under 2 centimeters long. In the leaf axils grow dense bunches of tiny flowers. There are no petals, but each flower has five thin shiny white

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s that look like tiny

fingernail A nail is a protective plate characteristically found at the tip of the digits (fingers and toes) of all primates, corresponding to the claws in other tetrapod animals. Fingernails and toenails are made of a tough rigid protein called alpha-k ...

s; the genus name ''Achyronychia'' is

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

for "chaff fingernail".Torrey, John, & Asa Gray. 1868. Proceedings of the American Academy of Arts and Sciences 7(2): 331.
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References

External links

Berkeley.edu - Jepson Manual TreatmentUSDA.gov - Plants ProfileBerkeley.edu - photo gallery
Caryophyllaceae Monotypic Caryophyllaceae genera North American desert flora Flora of Arizona Flora of Utah Flora of Nevada Flora of California Flora of Sonora Flora of Baja California Flora without expected TNC conservation status {{Caryophyllaceae-stub