Achyronychia is a monotypic genus; the only species, achyronychia cooperi
, inhabits the Mojave and Sonoran deserts, mostly in California, but also neighboring areas in west Arizona and far south Nevada. Flowers are small compared with the leaves; about 0.1 inches wide, formed of five greenish-white sepals, held upright to form a cup-shape, enclosing a group of up to 20 thread-like stamens, most of which are infertile (staminodes), and a two-lobed style. There are no petals. Flowers grow in clusters at the leaf nodes, of between 20 and 60 heads.
Stems are around 6 inches long, usually growing along the ground, and they may be hairless (usually), or lightly hairy. Plants produce many stems, radiating in all directions from the base. Leaves are fleshy, hairless, widest above the middle; they have a faint midvein, and a pair of tiny stipules at the base.