The following Participating Institutions are custodians for this species in the CPC National Collection:
University of California Botanical Garden
The conservation of Clarkia franciscana is fully sponsored.
Holly Forbes contributed to this Plant Profile.
Presidio clarkia is a slender annual herb, less than 0.4 m. tall with lavender-pink flowers that open from May to July. It is restricted to serpentine substrates in the San Francisco Bay area of California, where it is currently known from fewer than 5 sites in San Francisco and Alameda counties. Two sites within the San Francisco city limits are in the heavily used San Francisco Presidio (National Park Service) and are threatened by overuse by pedestrians and bicyclists, grass mowing before annual seed set, and the encroachment of non-native plants. The largest population, located 27 kilometers east of San Francisco in Alameda County, is in a regional park, but is similarly threatened by alien annual grasses and other non-native, invasive plants. Encroaching development potentially threatens a small population (NatureServe 2001).
Distribution & Occurrence
This species is restricted to grassland communities with serpentine soils. (USFWS 1998)
|Two extant populations are known from the San Francisco Presidio; one of these is thought to be introduced. While the number of plants fluctuates from year to year, the upper limit to the total numbers of plants reported in the Presidio is 8,000 in 1995. Three populations are known from the Oakland Hills in Alameda County, and are probably the remaining portions of one population that has been fragmented by roads and houses. The largest of these three populations had 4,000 to 5,000 plants in 1993, while the other two had 200 and 30 plants, respectively (USFWS 1998).|
Conservation, Ecology & Research
Non-native species invasions
Mowing before seed set
Shade from native and introduced shrubs and trees
Permanent vegetation transects were established in 1995 (USFWS 1998).
soil seed bank
techniques for opening new habitat for seeding
USFWS. (2002). Some Threatened & Endangered Plants Found Mainly in California. Sacramento Fish and Wildlife Office, U.S. Fish and Wildlife Service. http://sacramento.
Wood, M. (1996 (ongoing)). Focus on Rarities. [Web site] Yerba Buena Chapter, California Native Plant Society. http://www.cnps-yerbabuena.org/. Accessed: 2002.