Santa Barbara jewelflower, restricted to serpentine substrates in a small area of the southern coastal mountains of California, differs from the typical variety of C. amplexicaulis in its pale sepals.  The typical variety has purple sepals and is distributed across a wider geographic area, and a broader range of elevations and substrates. Photo by Dieter Wilken.

Caulanthus amplexicaulis var. barbarae range map.