About Achyronychia cooperi A.Gray
Achyronychia is a monotypic genus of flowering plant, holding only one species: Achyronychia cooperi, which has the common names onyxflower and frost-mat. This species is native to the Mojave and Sonoran Deserts, found in northern Mexico and the U.S. states of California, Nevada, Utah, and Arizona. In California, it has been recorded from San Diego, Imperial, Riverside, Los Angeles, San Bernardino, and Inyo Counties. In Arizona, it grows in Yuma, Mohave, Pima, Pinal, and Maricopa Counties. It has also been reported from Washington County, Utah, and Clark County, Nevada. Onyxflower is a small plant that forms a low, flat mat on the ground, and grows in sandy habitat. It sends out several prostrate stems spreading in all directions, each only a few centimeters long. Its thick, pale green leaves are paddle-shaped and less than 2 centimeters long. Dense clusters of tiny flowers grow in the leaf axils. These flowers have no petals, but each produces five thin, shiny white sepals that resemble small fingernails. The genus name Achyronychia comes from Greek, meaning "chaff fingernail".
