Identity
Unique IDELEMENT_GLOBAL.2.159353
Element CodePDBRA06290
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderCapparales
FamilyBrassicaceae
GenusBoechera
SynonymsArabis fecundaRollins
Other Common NamesMt. Sapphire rockcress (EN) Mt. Sapphire Rockcress (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 CommentsTreated by FNA (2010, vol. 7) in the genus Boechera.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-12-04
Change Date1988-12-16
Edition Date2024-12-04
Edition AuthorsShelly, J. (1989) ,rev. B. Heidel (1999), rev. Johnson, J. (2024)
Threat ImpactHigh
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences6 - 20
Rank ReasonsBoechera fecunda is a perennial herb endemic to Montana, USA. It is known from 27 occurrences in a small geographic area. A large part of this species' habitat is threatened by spotted knapweed (Centaurea maculosa), an aggressive, introduced weed.
Range Extent CommentsBoechera fecunda is endemic to Ravalli, Beaverhead, and Silver Bow counties in southwestern Montana. Range extent was estimated using herbarium specimens and NatureServe Network occurrence data collected between 1993 and 2024 (GBIF 2024, NatureServe 2024, SEINet 2024).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are 20 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Threat Impact CommentsSeveral factors may affect the long-term persistence of this species, including exotic weed encroachment, grazing, herbicide application, mining, and conifer encroachment.
The Montana Natural Heritage Program (2024) describes the threats to Boechera fecunda as follows:
Livestock grazing occurs at most sites, although fewer than half are reported to have heavy grazing. Direct herbivory has never been observed and is probably rare, however, soil crusts are beneficial to the species' survivorship at some sites; such crusts are often destroyed by livestock. Livestock can also adversely affect survivorship by trampling plants. Exclosure studies were conducted at two sites near the Big Hole River. At one site, Boechera fecunda increased in one grazing exclosure while decreased in another. Boechera fecunda establishes best when not competing with other species, and grazing may limit competition. It is interesting to note that some of the largest populations (Birch Creek and Jerry Creek) are in areas with the most intensive grazing.
Spotted knapweed (Centaurea maculosa) poses a major threat to populations in Ravalli County, where it has severely invaded this species' habitat. Studies indicate that knapweed reduces the successful establishment of sapphire rockcress seedlings. Most Boechera fecunda sites have severe infestations of spotted knapweed. Research on water use efficiency in this species has shown significant differences between low-elevation populations in the Bitterroot Valley and those at higher sites in Beaverhead County, suggesting that Bitterroot Valley populations, which are most threatened by weed encroachment, may be genetically distinct.
Roads are a major source of weed infestation, and road construction or other major disturbances can introduce or provide avenues for the introduction of weeds. Livestock can also be a significant vector for exotic weed encroachment. Currently, spotted knapweed does not occur at the Beaverhead or Silver Bow County sites, but it does occur in these counties and may become a problem.
Only one sapphire rockcress site is near an active mine, and has not been impacted to date. Other populations are near mining claims or inactive mines that could become active with improved extraction methods or increased demand for the minerals.
A few populations are located where conifer encroachment is expected to reduce habitat quality, and eventually displace existing populations without intervention.