BC Conservation Data Centre: Conservation Status Report
Botrychium paradoxum
two-spiked moonwort
| Scientific Name: | Botrychium paradoxum |
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| English Name: | two-spiked moonwort |
| Provincial Status Summary | |
| Status: | S3? |
| Date Status Assigned: | March 31, 2018 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | This species is extremely rare in British Columbia (only three or four known populations), and likely suffers substantial imminent threats from logging, invasive plants and herbivory. |
| Range | |
| Range Extent: | F = 20,000-200,000 square km |
| Range Extent Comments: | Using GIS tools, this species occurs over 37,088.7 sq km in BC. This range includes the fourth report at Armstrong Lake (photo on E-flora). |
| Area of Occupancy (km2): | C = 3-5 |
| Area of Occupancy Comments: | Using GIS tools, Index of Area of occupancy among the known populations in BC is four 2 km x 2 km grid cells (16 sq km). |
| Occurrences & Population | |
| Number of Occurrences: | AB = 1 - 20 |
| Comments: | At least four populations are known from British Columbia. No additional historic records are known. Discovered near Takla Lake North of Vanderhoof (R. Durand, pers. comm. 2013). There is also a report by J. Gatten on E-flora from Armstrong Lake (photo only; Gatten 2011). |
| Number of Occurrences with Good Viability / Ecological Integrity: | U = Unknown |
| Comments: | Little is known of the biology of Botrychium paradoxum (i.e., life history traits, any requirements for outcrossing, mycorrhizal relationships, responses to moderate or heavy disturbance, etc.), and population sizes are not known for two of the three known populations. Hence it is not currently possible to assess the number of populations having good viability. |
| Number of Occurrences Appropriately Protected & Managed: | A = None |
| Comments: | One of the three populations occurs in a private preserve managed by The Land Conservancy of British Columbia. It is not clear whether the Juniper Creek population lies within the Snowy Protected area. |
| Population Size: | U = Unknown |
| Comments: | One of the populations consists of a single known individual. All of the well-surveyed populations across the globally known range of Botrychium paradoxum are noted to be very small. It should not be assumed that any of the populations in BC are sizable to any degree. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Substantial, imminent threat |
| Comments: | More detailed information are needed from three or four known populations of Botrychium paradoxum in British Columbia, but it can be predicted that even small threats may have high negative impact given the small population sizes produced by this species. Identifiable threats include invasive plants, grazing, logging activity (as with the frequent use of potential Botrychium habitats as logging landings). Herbivory by native species (such as ground squirrels) may also be a threat to individuals of B. paradoxum, but ground squirrel activity may help maintain some Botrychium habitats. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Comments: | Baseline data are not available that would allow assessment of short-term trends. |
| Long-Term Trend: | U = Unknown |
| Comments: | Baseline data are not available that would allow assessment of short-term trends. |
| Other Factors | |
| Intrinsic Vulnerability: | U=Unknown |
| Comments: | Botrychium paradoxum may be moderately vulnerable, owing to the species' normally small population sizes. |
| Environmental Specificity: | U=Unknown |
| Comments: | Environmental specificity of Botrychium paradoxum remains poorly understood among the British Columbia populations. Across its global range it is known mostly from subalpine meadows, in stands of Epilobium angustifolium, and in high elevation willow stands. |
| Other Rank Considerations: | The portion of the global population British Columbia is small, so stewardship responsibility is low for the province. However Botrychium paradoxum is globally rare, and endemic to western temperate Cordilleran North America. All populations of globally rare species are greatly valuable in maintaining total genetic diversity and to maintain the most natural geographical range extent possible. Botrychium paradoxum is thought to be a parental species to the rare hybrid B. x watertonense. That species has yet to be found in British Columbia, but should be sought among B. paradoxum populations (Farrar, D. 2012. Botrychium paradoxum. Unpublished web-based document http://www.public.iastate.edu/~herbarium/botrychium/B-paradoxum.pdf [Accessed March, 2012]). |
| Information Gaps | |
| Research Needs: | Much remains to be learned about the biology of this species, specifically as to its reproductive strategies and life history traits, its ability to withstand changes to its environment, and about the degree to which it is able to remain in dormancy long-term through unfavourable conditions. Baseline population demographic data are also needed. |
| Inventory Needs: | Potential habitats should be searched at appropriate times during the growing season. Habitats in particular need of surveys are subalpine meadows, fireweed stands, and upper elevation shrub stands. In southwestern Alberta, this species inhabits pocket grasslands, and so Botrychium paradoxum may also be found in like habitat in British Columbia. |
| Stewardship | |
| Protection: | Each known population should be protected from human-caused damage to habitats, and the habitats should be maintained in as natural condition as possible. |
| Management: | Occurrences should be maintained in as natural condition as possible. Any efforts to control invasive species should avoid herbicide use, or if herbicide use is absolutely necessary, the herbicides should be applied at times when Botrychium paradoxum and any other rare Botrychium species are dormant below-ground, and all native plants should be protected from herbicide spray and drift. Herbicides used should be those that degrade rapidly and do not remain potent in the soil. |
| Version | |
| Author: | Bjork, C. & R. Batten |
| Date: | March 29, 2012 |
| References | |
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Batten, R. 2018. Vascular plant GeoCAT range extent and index of AOO maps supporting status assessment 2017_18 for British Columbia Conservation Data Centre. March 2018. Victoria, BC. 450 pp.
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British Columbia Conservation Data Centre. Botany Program. 2000. Database containing records of rare plant collections and observations in the province of British Columbia.
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Farrar, D. 2012. Botrychium paradoxum. Unpublished web-based document http://www.public.iastate.edu/~herbarium/botrychium/B-paradoxum.pdf [Accessed March, 2012]
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Gatten, J. 2011. In Klinkenberg, Brian. (Editor) 2013. E-Flora BC: Electronic Atlas of the Flora of British Columbia [eflora.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver.[April 19th, 2013].
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2012. Conservation Status Report: Botrychium paradoxum. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 7, 2026).