Ambrosia Pumila (San Diego Ragweed)
Endangered Plant Species
Ambrosia pumila (San Diego ragweed) is a clonal herbaceous perennial plant occurring in southern California from northwestern Riverside County, south through western San Diego County, to northwestern Baja California, Mexico. The species is found primarily on upper terraces of rivers and drainages; however, several patches of the plant occur within the watershed of a large vernal (ephemeral) pool at the Barry Jones (Skunk Hollow) Wetland Mitigation Bank in Riverside County.
Cause of Endangerment
The primary threats at that time were urban development and highway and utility corridor construction and maintenance, inadequacy of regulatory mechanisms, nonnative plants, mowing or discing, and human encroachment.