Fritillaria gentneri Population Monitoring in Josephine County

2012 IAE conservation crew interns Guy and Charlotte conducting a demographic survey of Fritillaria gentneri in Josephine county.

In the third week of April, the conservation crew monitored a population of Gentner’s Fritillary, scientific name Fritillaria gentneri Gilkey, on Picket Creek in the Siskiyou Range to the southwest of Grant’s Pass, Oregon.  Our monitoring of this species is tied to the flowering season because it cannot be distinguished from the two ‘parent’ species F. recurva (scarlet fritillary) and F. affinis (chocolate lily) vegetatively and the distribution of these three species overlap throughout the range of fritillary.

Fritillaria gentneri found in our monitoring was counted as an R2 meaning "a reproductive individual with two blooms. The highest ranking we recorded for number of flowers we found on one individual this year was an R7!

            Gentner’s Fritillary is a rare lily endemic to a limited range in the Klamath-Siskiyou region of southern Oregon and northern Californa.  It is listed as an endangered species by both the state of Oregon and the U.S. Fish and Wildlife Service. A detailed description of Genter's frittilary can be found in 2011’s blog entry for Gentner's fritillary via this link. http://research.appliedeco.org/2011/04/population-monitoring-of-fritillaria.html

There are several aspects that lead to the vulnerability of Gentner’s Fritillary.  It is a mid-successional species found in dry hillsides in open canopies of oak woodlands and chaparral shrub communities.  It is also present mixed hardwood forests, coniferous forests and grasslands at elevations, and in all of these ecotypes from 600 to 4,450 ft.   Fire suppression in many of these normally fire prone habitats has lead to encroachment by trees and shrubs which at lower densities would provide useful cover.  Housing and agricultural development, exotic grass encroachment, yellow star thistle (Centaurea solstitialis) and associated herbicide treatments, horticultural collecting, mining, wildlife grazing, logging, and possible climatic limitations on reproduction are additional pressures on the species.

Gentner's fritillary has low genetic diversity due to the relatively few and isolated events of hybridization between scarlet fritillary and chocolate lily that created the species.  Many populations of Gentner's fritillary are sterile clones that propagate only by producing numerous tiny bulblets.  Viable seed is known to be produced in larger populations because of the presence of sufficient genetic variation to navigate the substantial genetic safeguards present in many lilies that inhibit inbreeding. Efforts at creating viable seed have been successful when cross-pollinating from different populations.

A view uphill typical of the lower slope of our Picket creek monitoring site, oak grassland with a steep grade.

The steep and shallow soils with mild serpentine influence contribute to the set of conditions at Pickett Creek that provide suitable habitat for Gentner's fritillary.  It's presence at this site with shallow soils and dry summers is indicative of F. gentneri’s drought tolerance, and the serpentine influence in the soils reveal the species’ tolerance for adverse soil chemistry.  Serpentine soils are high in heavy metals and trace minerals, low in vital nitrogen, phosphorus and potassium, and have a low calcium to magnesium ratio, all factors that create conditions normally toxic to most plant species.

           Gentner's fritillary stands a good chance for recovery through the continued monitoring and conservation efforts by government agencies and entities like IAE, and the raising of public awareness of this charismatic species.