Pseudobahia peirsonii

Endemic to California's Central Valley. There are currently 36 occurrences but most are very small (less than 250 individuals) and most of the plants are concentrated in 3 general areas. Residential development is the primary threat to the species. Other threats include road maintenance projects, and recreational activities, and competition from non-native plants.

Known only from California (FNA 2006c).

The greatest threats to this species are residential and agricultural development, since about 89% of extant occurrences are found on private lands where they receive little protection (USFWS 2007). Lake Success is a recreational lake whose creation extirpated some of this species' habitat and occurrences, and where flooding continues to be a threat to the remaining local occurrences (USFWS 2007). Heavy recreational activity along the shoreline, a new dam and wider spillway are also an immediate threat (USFWS 2007). Only the most excessive of trampling and consumption due to cattle grazing is considered a threat, otherwise profitable, moderate regimes are seen as positive as they help discourage development and regulate invasive plants (USFWS 2007). Non-native plants include Avena fatua, Brassica kaber, Bromus mollis, Bromus madritensis ssp rubens, and Erodium circutarium (USFWS 2007). Other threats include road Maintenance and Widening, Transmission line rights of way and severe, prolonged drought (USFWS 2007).