The following Participating Institutions are custodians for this species in the CPC National Collection:
Rancho Santa Ana Botanic Garden
San Diego Zoo Global
The conservation of Brodiaea filifolia is fully sponsored.
Sula Vanderplank contributed to this Plant Profile.
Brodiaea filifolia (thread-leaf Brodiaea) is a geophyte (corm-forming perennial herb) in the lily family (Liliaceae)(Keator 1993), that is only visible above ground for a few months of the year. It is 2-4 dm tall with a longer scape, narrow leaves and a fibrous-coated corm, flowering from May to June, with purple flowers. All Brodiaeas tend to have very similar corolla morphologies, however B. filifolia is readily distinguished by its threadlike (filiform) reflexed staminodes, short filaments and spreading perianth (FWS 1998, Chester et al 2007). This species often occurs around vernal-pool complexes and wetlands of Southern California, but it is also known from areas of heavy clay soil or cobbly clay.
Brodiaea filifolia is listed as endangered by the State of California (1982) and was federally listed as threatened by the U.S. Fish and Wildlife Service in 1998. Critical habitat was designated in 2005 in Los Angeles and San Diego Counties. There is also a Multiple Species Habitat Conservation Plan (MSHCP WRC 2001) in place for Western Riverside County, and some areas of San Diego County, including Chula Vista (MSCP 2003).
Distribution & Occurrence
Brodiaea filifolia has considerable water-dependence and is usually found in on gentle slopes in mesic southern needlegrass grassland and alkali grassland plant communities (FWS 1998). This species occurs at 0-300 ft in elevation, on clay, loamy sand, or alkaline silty-clay soils, and is most commonly found growing with perennial grasses.
Brodiaea santarosae is a morphologically similar species (larger flowers, longer filaments and erect staminodes) of adjacent and overlapping range that has been thought to be a hybrid introgression of B. filifolia and B. orcuttia it has only been recorded on basalt soil and is usually found on slightly drier sites (Chester et al 2007).
|The exact number of extant populations is difficult to assess for several reasons. Concepts of occurrences and populations have varied widely and have been reported very differently by different biologists. The Federal listing (FWS 1998) noted thirty-seven extant populations, however, with the discovery of Brodiaea santarosae there are now many mis-identified, and un-vouchered populations, potentially with more than one species occurring; and two populations recently added after it was confirmed that they were not of hybrid origin (Chester et al, 2007). Population counts are extremely hard to assess as in any given year only a small number of corms will have above-ground activity. In one instance only 20 individuals were seen, but during a transplanting effort more than 8,000 corms were found in the soil (MSHCP WRC 2001). Fewer than 500 individuals have been observed within half of the populations, and populations exceeding 5,000 flowering stalks have been reported in only six populations (MSHCP WRC 2001).|
Conservation, Ecology & Research
There is no current recovery plan for this species, however its habitat requirements fall under the Vernal Pools of Southern California Recovery Plan:
Populations that were previously disced for fire suppression should be closely monitored for recovery. Population disturbance should be minimized at all sites. A recovery plan should be developed for this species, especially for areas that previously received severe impacts from fire management regimes.
A seedbank should be established to enable future restoration or revegetation efforts.
Niehaus, T.F. 1971. A Biosystematic Study of the Genus Brodiaea (Amaryllidaceae). Los Angeles: University of California Press.
Roberts, F.M.; White, S.D.; Sanders, A.C.; Bramlet, D.E.; Boyd, S. 2004. The Vascular Plants of Western Riverside County: An annotated Checklist. San Luis Rey, California. F.M. Roberst Publications.