The following Participating Institutions are custodians for this species in the CPC National Collection:
Rancho Santa Ana Botanic Garden
The conservation of Caulanthus californicus is fully sponsored.
Dieter Wilken contributed to this Plant Profile.
California jewel flower, an annual in the mustard family, germinates after winter rains and flowers from February through May. Plants are typically branched, with clasping leaves. The striking inflorescences appear to have flowers that appear purple or white, sometimes green- to purple-tinged near the sepal tips of upper flowers. Open flowers bear white to greenish sepals, and narrow, crinkly, white petals (Rollins 1993). However, the dark purple terminal flower buds remain closed, and may provide a striking contrast to reproductive flowers for the purpose of attracting insects. Once widespread in the southern San Joaquin Valley and adjacent foothills, it is now restricted to three general areas of Fresno, San Luis Obispo, and Santa Barbara counties. Most of the historic locations, including over documented 40 occurrences, have been lost primarily as a result of agricultural development and grazing (Taylor and Davilla 1989). California jewel flower has sometimes been placed in a separate genus (Stanfordia) based on the compression of the fruit and the seeds (Buck 1993; Rollins 1993). Most current California references use the name Caulanthus californicus (Anonymous 2008a, 2008b; Buck 1993).
Distribution & Occurrence
Typical habitats include flats, alluvial fans, and gentle slopes with sandy to gravelly soils (Taylor 1983). Typical plant communities include open grasslands and shrublands dominated by salt-bush (Atriplex) or Mormon tea (Ephedra).
|The number of plants varies from year to year, depending on rainfall in the preceding winter. During drought years, few if any plants may be present (Twisselmann 1967; Williams et al. 1998). About 35 extant populations were estimated to be extant in the mid 1990s. In some areas many populations were found in close proximity, with numbers of individuals ranging from as few as 3 to over 2,000 in others.|
Conservation, Ecology & Research
Potential agricultural development
Random loss of small, local populations
Development of a propagation protocol to be applied to in situ conditions
Abrams, L.; Ferris, R.L. 1944. Illustrated flora of the Pacific states. Volume II. Stanford. Stanford University Press. 635 p.
Anonymous. 2008a. Vascular plants, bryophytes, and lichens list. Sacramento. California Department of Fish and Game, Natural Diversity Database, Sacramento. Quarterly Publication. 70.
Hoover, R.F. 1970. The vascular plants of San Luis Obispo County, California. Berkeley. University of California Press. 350p.
Rollins, R.C. 1993. The Cruciferae of continental North America. Stanford University Press. 976p.