Castilleja grisea

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Castilleja grisea, Santa Clemente Island endemic

Castilleja grisea San Clemente Island endemic. It is a rare species of Indian paintbrush known by the common name San Clemente Island Indian paintbrush. San Clemente Island is owned by the US Navy so the Navy is involved in a management program to recover this species. The San Clemente Island Indian paintbrush is a perennial herb coated densely in long gray hairs. The highly branching stem grows 40 to 60 centimeters tall and bears linear leaves each a few centimeters long. The inflorescence is made up of layers of bracts one to two centimeters long, gray-green in color at the bases and tipped with greenish yellow. Between the bracts emerge dull yellow pouched flowers. The fruit is a capsule about a centimeter long containing tiny seeds with netted surfaces.

Due to steep terrain of San Clemente Island the exact abundance of Castilleja grisea is not currently known. Recent surveys have discovered new populations of this species. Surveys in 2007 estimate more than 10,000 plants existing. This plant has been a federally listed endangered species since 1977, when it was one of the first species to be designated so. The plant's population had been drastically reduced by the activity of the feral goats. Its populations has increased at least ten-fold since the removal of these non-native herbivores. The species has recovered so well through management programs by the Navy, it was recommended for down listing during the last review conducted by the United States Fish and Wildlife Service. Remaining threats include erosion, invasive grasses, and wildfire from military exercises.

The species has a relatively high genetic variability for an uncommon island endemic. This and its steady recovery from low numbers give an optimistic outlook for the species' recovery.



Island Collections~
ISLAND COLLECTOR INSTITUTION DATE NUMBER SPECIMEN
San Clemente Island T. S. Brandegee UC August 24, 1894 UC-103538 Castilleja grisea Plants
San Clemente Island Nell Murbarger UC April 1936 UC-557802 Castilleja grisea Plants
San Clemente Island Francis H. Elmore RSA February 18, 1939 RSA-576130 Castilleja grisea Plants