Post-wildfire response of Shasta snow-wreath

Shasta snow-wreath (Neviusia cliftonii) is a rare shrub of the Rosaceae: tribe Kerrieae endemic to the southeastern Klamath Mountains in the general vicinity of Shasta Lake, Shasta County, California.The species was discovered less than 30 years ago (Shevock et al. 1992;Taylor 1993) and initially considered a limestone obligate.Subsequent occurrences have also been found on various non-limestone substrates (Lindstrand and Nelson 2005a, b, 2006;DeWoody et al. 2012;Jules et al. 2017).The only congener, Alabama snow-wreath (Neviusia alabamensis), also has a limited range restricted to several disjunct populations in the southeastern United States and occurs on limestone and non-limestone sedimentary substrates (Long 1989;Freiley 1994).Shasta snow-wreath is deciduous and produces flowers with showy white stamens, five toothed green sepals, and rarely, one to three narrow white petals.Based on our observations since its discovery, the species reproduces vegetatively, forming thickets of stems from the root system.Despite observations of developing achenes, no viable seed nor seedlings have been collected or observed.We are not aware of any pollinators and the blooms lack detectable scent.Genetic sampling at 21 Shasta snow-wreath populations conducted during 2011 revealed low genetic diversity within populations, high variation between populations, and low overall genetic diversity, supporting the theory that sexual reproduction is less common than vegetative reproduction and that there is, at best, low gene flow within and between populations (DeWoody et al. 2012).Alabama snow-wreath is also only known to reproduce vegetatively, in the wild (Freiley 1994).Shasta snow-wreath currently holds a California Rare Plant Rank of 1B.2 (CDFW 2020) and also is considered a Sensitive species by the Region 5 U.S. Department of Agriculture Forest Service and the California Region of U.S. Department of Interior Bureau of Land Management.Recent petitions have been submitted to the U.S. Fish and Wildlife Service and California Fish and Game Commission seeking species protection under the Federal Endangered Species Act and California Endangered Species Act, respectively (CFGC 2019; Roche 2019; USFWS 2019).