Atriplex coronata var. notatior

Atriplex coronata var. notatior is known from 15-16 occurrences, primarily located in two drainages in western Riverside County, southern California. It appeared to decline approximately 70% between 1992 and 1998; habitat destruction and fragmentation have continued since then. The majority of its habitat has been impacted by intensive cultivation, urbanization, watercourse channelization, and/or filling. Much of the remaining habitat is impacted by dryland farming, plowing, discing for weed abatement or fire control, manure and sludge dumping, grazing, off-highway vehicles, invasive plants, and/or alteration of key hydrological processes. In addition, large-scale commercial and urban development, flood control, and transportation projects have been proposed for the area where it occurs. The Western Riverside Multi-Species Habitat Conservation Plan may reduce the severity of some of these threats over time, although it could take up to 25 years for this taxon to be afforded the full conservation benefits outlined in this Plan.

Restricted to the San Jacinto, Perris, Menifee, and Elsinore Valleys of western Riverside County, California. Occurrences are associated primarily with the San Jacinto River and Old Salt Creek tributary drainages, with an additional occurrence near Lake Elsinore (USFWS 2008).

Approximately 15-16 occurrences are believed extant. Because of the close proximity of some occurrences and the dynamic nature of the habitat, the U.S. Fish and Wildlife Service (2008) considers these to comprise four "occurrence complexes."

The majority of this taxon's habitat has been impacted by a combination of intensive cultivation, urbanization, watercourse channelization, and/or filling. Much of the remaining habitat is impacted by dryland farming, plowing, discing for weed abatement or fire control, manure and sludge dumping, grazing, off-highway vehicles, and/or alteration of key hydrological processes. Invasive competitors such as Salsola australis and Brassica nigra are also a threat in some areas, brought on by reductions in soil alkalinity from manure/sludge dumping. Other invasives such as Crypsis schoenoides have been seeded as food for waterfowl within some parts of the range, where they pose a competitive threat once established. Protections afforded this taxon under the Western Riverside Multi-Species Habitat Conservation Plan (MSHCP) may reduce the severity of some of these threats over time, as the MSHCP Conservation Area will eventually include 45-77% of the habitat identified by the U.S. Fish and Wildlife Service as essential to the conservation of this taxon. However, it could take twenty-five years to complete Conservation Area assembly and, during that time, impacts associated with MSHCP Covered Activities (e.g. agricultural activities, flood control, highway and utility maintenance) may continue. Particularly in areas not currently identified as Public or Quasi-Public lands under the MSHCP, further habitat destruction by proposed commercial and residential development, transportation infrastructure, pipelines, and flood control projects remains a major threat (USFWS 2008).