Regularity: Regularly occurring
Global Range: Endemic to the Middle Fork of the Tule River drainage (Tulare County) in Giant Sequoia National Monument (Linton 2012).
Comments: Rock outcrops within in Canyon Live Oak woodland & chaparral on metamorphic carbonate substrate (Limestone & Marble).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 5
Life History and Behavior
NatureServe Conservation Status
Rounded Global Status Rank: T2 - Imperiled
Reasons: Known from only a couple sites in Tulare County, California. Anthropogenic threats are minimal because the sites are relatively inaccessible, but illegal harvest is a potential risk. The inaccessibility of sites also limits the extent of survey for potential habitat.
Environmental Specificity: Narrow. Specialist or community with key requirements common.
National NatureServe Conservation Status
Rounded National Status Rank: N2 - Imperiled
Global Short Term Trend: Relatively stable (=10% change)
Degree of Threat: Low
Comments: Sites are relatively inaccessible and therefore protected from threats such as illegal collection.
Names and Taxonomy
Comments: Editorial comments entered in the Jepson Interchange (online as of September 2011) conclude, after consultation with Kanchi Ghandi, Nancy Morin, Dan Nicolson, International Plant Names Index colleagues, among others regarding the correct Latin for the epithet of this subspecies, that 'costatifolia' is the most appropriate (those proposed and sometimes published were costafolia, costifolia, costaefolia, costiformifolia, and costatifolia).