Identity
Unique IDELEMENT_GLOBAL.2.139432
Element CodePDSAX0U230
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRosales
FamilySaxifragaceae
GenusMicranthes
SynonymsSaxifraga tischiiSkelly
Other Common NamesOlympic saxifrage (EN) Saxifrage de Tisch (FR) Tisch's Saxifrage (EN)
Concept ReferenceKartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Taxonomic CommentsMicranthes tischii (Skelly) Brouillet & Gornall was first described in 1988 as Saxifraga tischii Skelly from the Olympic Mountains (Washington) and Vancouver Island (British Columbia) in western North America (Skelly 1988). Brouillet and Gornall (2007) outline that as a result of recent phylogenetic studies, the genus Saxifraga, has been split into two genera: Saxifraga L. sensu stricto and Micranthes Haw. The new name for this plant is Micranthes tischii (Skelly) Brouillet & Gornall, which has been followed since 2007 (Flora of North America Editorial Committee 2009). This species is closely related to Micranthes rufidula Small, but differs with its unusual persistent green, not clawed petals (Flora of North America Editorial Committee 2009).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-12-22
Change Date2023-12-22
Edition Date2023-12-22
Edition AuthorsNiese, J., rev. Maybury/Gamon (1996), rev. L. Morse (2004), rev. K. Gravuer (2010), rev. M. Anions (2010), rev. A. Frances (2020), rev. C. Nordman (2023).
Threat ImpactMedium - low
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences6 - 20
Rank ReasonsOlympic Saxifrage (Micranthes tischii) is a highly specialized regional endemic narrowly restricted to cool, shady ledges or rock crevices in subalpine or alpine sites of the Pacific Northwest region of North America. There are fewer than 20 known locations, including in the Olympic National Park in northwestern Washington, and in Strathcona Park on Vancouver Island and in the Skagit Valley Provincial Park area of the North Cascade Range, of southwestern British Columbia. The remote, rugged terrain this species inhabits protects it from most direct human disturbance. However, it is threatened by recreation impacts, stochastic events due its small population size, and climate change.
Range Extent CommentsOlympic Saxifrage (Micranthes tischii) occurs in northwestern North America, in the Pacific Northwest the United States (northwestern Washington) and southwestern Canada (southwestern British Columbia). It is a narrow regional endemic, only known from three disjunct areas (Skelly 1988). In Washington, the species occurs in the Olympic Mountains (in Clallam and Jefferson counties). In British Columbia, the species occurs on Vancouver Island and in the Skagit Valley Provincial Park area of the North Cascade Range. Range extent was estimated to be 41,000 square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1985 and 2023 (GBIF 2023, iNaturalist 2023, NatureServe 2023, SEINet 2023).
Occurrences CommentsBased on NatureServe Network occurrence data, herbarium records, and photo-based observations documented between 1985 and 2023, and anecdotal evidence, there are about 13 and between 6 and 20 occurrences of Olympic Saxifrage rangewide. There are about five occurrences, plus several historical occurrences in the Olympic Peninsula of western Washington. There about five occurrences on Vancouver Island and four in the Skagit Valley Provincial Park area of the North Cascade Range, in southwestern British Columbia (GBIF 2023, iNaturalist 2023, NatureServe 2023, SEINet 2023).
Threat Impact CommentsThe rugged terrain (rock ledges, crevices) in remote locations that this species inhabits probably protects it from human disturbance, however many of these mountains are popular destinations of recreational hikers, mountain climbers, and winter sports. One location has an active mining operation nearby. It is not known whether any of these activities impact this species. Other threats include: frost heave, landslides, climate variability (drought) and climate change, and by stochastic events due its small population size (Wershow and DeChaine 2018).