Coleogyne ramosissima or blackbrush, is a low lying, dark grayish-green, aromatic,[2] spiny, perennial, soft wooded[2] shrub, native to the deserts of the southwestern United States.

[4] This plant forms vast pure stands across the desert floor and on scrubby slopes, giving the landscape a uniform dark-gray color.

The leaves are inversely lanceolate, up to 3/8" long, have a small point at the tip, and are arranged in opposite pairs along the stem,[4] which is uncommon in members of the rose family.

There are no petals, but the sepals remain after the flower opens, surrounding the patch of whiskery stamens and the central pistil.

A narrow range of temperature and moisture is required for the reproduction of this species, so it is sporadic, but the plants are hardy and long-lived.