North American Warm Desert Cienega

Geology

While the cienegas themselves often occur within Quaternary alluvium, the springs that feed the marshes and moist-soil habitats emanate from contacts often of Cretaceous limestone with less permeable formations.

Landform

Spring runs and draws fed by freshwater springs.

Soils

Often associated with Draw (Desert Grassland) Ecological Sites.

Parent Description

This predominately herbaceous system occurs on drainages fed by freshwater springs. Evaporative processes may create saline conditions leading to the presence and/or dominance of species such as Sporobolus airoides (alkali sacaton), Distichlis spicata (saltgrass), Sesuvium verrucosum (winged sea purslane), and Trianthema portulacastrum (desert horse purslane), and Limonium limbatum (bordered sea-lavender). Other moist-soil species include Schoenoplectus pungens var. longispicatus (American bulrush), Juncus spp. (rushes), and Eleocharis spp. (spikerushes). Composition of the occurrence is dependent on the depth and availability of water associated with the originating spring. At some sites, rare species such as Helianthus paradoxus (Pecos sunflower), Nesaea longipes (longstalk heimia), and Agalinis calycina (Leoncita false foxglove) may be found. The non-native grass Cynodon dactylon (Bermudagrass) is often encountered.