The San Clemente Island indian paintbrush (Castilleja grisea) is one of 13 plant species endemic to the Island of San Clemente, California . The San Clemente Island paintbrush is a somewhat shrubby plant with yellow blooms  associated with the sage scrub community on the island . It is likely partially parasitic on shrubs in the “goldenbrush” family .
In 1939, a collector described the San Clemente Island paintbrush as common on the lower slope of bluffs on the southeast coast of the island . By 1963, it was described as “occasional on the southeast coast and rare on canyon-sides elsewhere” . By 1978 few plants could be found . A survey of the entire island conducted in 1979 found a total of 450 plants . The decrease in the number of San Clemente Island paintbrush was largely due to grazing and trampling by feral goats and pigs . Although livestock from early ranching on the island had been removed prior to the establishment of a military training facility in the 1930s, some feral goats and pigs remained and their populations increased dramatically . The paintbrush plants that survived the presence of these animals were often located on steep cliff faces where they couldn’t be reached .
Programs to eradicate feral animals on the island were initiated in 1962 . These efforts were unsuccessful, however, until renewed efforts in the 1980s led to the extirpation of feral animals on the island in 1992 . Following the elimination of these animals, paintbrush populations began to increase and expand . In 1996 and 1997, 77 populations of San Clemente Island paintbrush were mapped on the island, totaling more than 3,500 plants . Recent mapping efforts indicate continued progress towards recovery . Since 1997, a dramatic increase in the number of paintbrush plants has taken place and the paintbrush has colonized new areas of the island .
 Center for Plant Conservation. CPC National Collection Plant Profile: Castilleja grisea. Website <http://www.centerforplantconservation.org/ASP/CPC_ViewProfile.asp?CPCNum=817> accessed January, 2005.
 Mohlenbrock, R.H. 1983. Where Have All the Wildflowers Gone? A Region-by-Region Guide to Threatened or Endangered U.S. Wildflowers. Macmillan Publishing Co. Inc. NY.
 Endangered Species Information System. 1996. Fish and Wildlife Information Exchange, VA Tech. San Clemente Island Indian Paintbrush. Website <http://fwie.fw.vt.edu/WWW/esis/lists/e701029.htm> accessed January, 2005.
 Helenurm, K., R West, and S.J. Burckhalter. 2005. Allozyme Variation in the Endangered Insular Endemic Castilleja grisea. Annals of Botany 95(7):1221-1227.
 Junak S.A. and D.H. Wilken. 1998. Sensitive plant status survey, Naval Auxiliary Landing Field, San Clemente Island, California. Santa Barbara, CA: Santa Barbara Botanic Garden.
 Junak, S.A. 2005. Personal communication with Steven Junak, Santa Barbara Botanic Gardens.