Information comes from the 1988 publication "A management plan for the Springtown Alkali Sink Wetlands and the endangered Cordylanthus palmatus" by Coates, R, Showers, M, and Pavlik, B, available at the California Dept. Fish & Game website: http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3109

I think this article was re-published 5 years later (or possibly first published) under the name "Management plan for an alkali sink and its endangered plant Cordylanthus palmatus", https://doi.org/10.1007/BF02393800