The crinite mariposa lily (Calochortus coxii) is a rare plant that is listed as endangered by the state of Oregon.  This species is endemic to a ten-mile serpentine ridge system between Myrtle Creek and Riddle, OR.  Though 24 populations of crinite mariposa lily were identified in the early 1990’s, the majority of these had not been revisited and their status was unknown. 

In 2011, IAE initiated a study working with the Bureau of Land Management (BLM) to survey all known occurrences of crinite mariposa lily on BLM land, estimate their size and extent, and document potential threats to these populations.  Crinite mariposa lily was only present at six of the nine sites where this species had previously been documented.  At the three sites where it was no longer present, the habitat was dominated by invasive grasses and there was evidence of human-caused disturbances.  We counted significantly fewer crinite mariposa lilies than had previously been estimated at all but one of the remaining populations.  Additionally, the spatial extent of these populations was much narrower than had been previously indicated.  Our research suggests that crinite mariposa lily may be at a higher risk of extinction than previously thought.  We found strong associations with native species, suggesting that maintaining high habitat quality at these sites may be necessary for the perpetuation of this rare endemic of serpentine soils. 

IAE will continue its partnership with BLM to monitor population trends and assess potential threats to crinite mariposa lily and inform management of this rare species.  For our most recent annual report, please click here.

If you have any questions about this project, please contact Erin Gray at erin@appliedeco.org or 541-753-3099 ext. 403.