Warm-Desert Arroyo Riparian Scrub [M092] occurs primarily in the Chihuahuan Desert ecoregion, but extends northward into the Colorado Plateaus and High Plains and Tablelands ecoregions and westward into the Madrean Archipelago and Arizona/New Mexico Mountains ecoregions. It is primarily an open shrubland habitat with patches of vegetation occurring within and along the edges of ephemeral desert washes, dissected piedmonts, mesas, plains, and basin floors. Desert willow (Chilopsis linearis), Apache plume (Fallugia paradoxa), and littleleaf sumac (Rhus microphylla) are the typical dominants, with singlewhorl burrobrush (Hymenoclea monogyra), catclaw acacia, little walnut (Juglans microcarpa), and splitleaf brickellbush (Brickellia laciniata) as common associates. The herbaceous layer is usually sparse with widely scattered grasses and forbs. This habitat is associated with flash flooding and rapid sheet and gully flows that scour channel bottoms. The vegetation is sparse from both the high impact of flooding and the lack of moisture for the rest of the year.