BC Conservation Data Centre: Conservation Status Report
Orthocarpus imbricatus
mountain owl-clover
| Scientific Name: | Orthocarpus imbricatus |
|---|---|
| English Name: | mountain owl-clover |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | April 30, 2021 |
| Date Last Reviewed: | April 30, 2021 |
| Reasons: | Orthocarpus imbricatus only occurs in one location in a mountanous area of Vancouver Island. Additional populations are possible, but there are few suitable habitats within its range. The population is unlikely to be threatened by human activity, but it may be vulnerable due to a single extant population, or other factors. |
| Range | |
| Range Extent: | A = <100 square km |
| Range Extent Comments: | The estimated extent of occurrence is < 20,000 square metres. |
| Area of Occupancy (km2): | AD = 1-25 |
| Area of Occupancy Comments: | This species occurs in 1 2 km x 2 km grid (4 km sq). |
| Occurrences & Population | |
| Number of Occurrences: | A = 1 - 5 |
| Comments: | Only one verified extant occurrence is known for this species, though other locations are possible. The habitat requirements are somewhat restricted so it is not expected many more locations in B.C. (H. Roemer pers. comm. 2008). |
| Number of Occurrences with Good Viability / Ecological Integrity: | B = 1 - 3 |
| Comments: | The single known population is fairly large, has persisted for over 30 years and does not appear to be threatened in any way. The probability of peristence over the next 20 years is excellent, if current conditions prevail. |
| Number of Occurrences Appropriately Protected & Managed: | A = None |
| Comments: | The site is not within a formally-designated protected area, but the habitats where it occurs are too steep for road-building and are therefore isolated from adjacent land uses, such as logging. |
| Population Size: | CD = 250 - 2,500 individuals |
| Comments: | The estimated population size of 1,000 is based on counts of seven subpopopulations in 2008. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Unknown |
| Comments: | Orthocarpus imbricatus grows on a steep, remote mountain slope that is not currently threatened by human activity. The native species composition is diverse at this location and there are no invasive exotic species present. However, this is the only reported population of this species in B.C. and may be vulnerable to stochastic events that could result in the loss of this population. Climate change could also be a threat, but is one that is difficult to assess (J. Penny, pers. comm. 2008). |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | Trends are impossible to evaluate based on current information, but the population and habitat are probably stable as the species has been known for more than 30 years and no development has taken place, or is likely to take place, at this location. |
| Long-Term Trend: | U = Unknown |
| Comments: | Insufficient historical information is available to determine long-term trends, |
| Other Factors | |
| Intrinsic Vulnerability: | U=Unknown |
| Comments: | It is unknown whether this species is intrinsically vulnerable. Like other owl-clovers, Orthocarpus imbricatus may be semiparasitic, extracting water and nutrients from host plants. This relationship could be limiting if the host plant becomes threatened. |
| Environmental Specificity: | C=Moderate. Generalist or community with some key requirements scarce. |
| Comments: |
The key requirements are unknown, but the species appears to be restricted to the rockier portions of subalpine meadows on very steep terrain where shallow soils and dry summer conditions prevail (H. Roemer pers. comm. 2008). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | The population ecology and reproduction of this species requires study in order to understand potential limiting factors, pollinator restrictions, recruitment and dormancy. An understanding of population viability and fluctuations is needed. Habitat analysis aimed at determining environmental specificity is also needed. |
| Inventory Needs: | Surveys should be undertaken in high suitability habitats identified by ecosystem mapping, to find new sites and better define population distribution. In addition to Little Mount Hooper, P-Mountain was also surveyed during the 2008 inventories. This site has extensive lush south-facing meadows, open talus/scree and fractured bedrock with no or only shallow soil material. All three types were examined for Orthocarpus imbricatus and though the latter habitat was similar physically and in its vegetation to that found on Little Mt. Hooper, this species was not found (H. Roemer pers. comm.). |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Donovan, M. |
| Date: | October 08, 2008 |
| References | |
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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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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. 2008. Conservation Status Report: Orthocarpus imbricatus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 13, 2026).