BC Conservation Data Centre: Conservation Status Report
Hypericum majus
large Canadian St. John's-wort
| Scientific Name: | Hypericum majus |
|---|---|
| English Name: | large Canadian St. John's-wort |
| Provincial Status Summary | |
| Status: | S5 |
| Date Status Assigned: | April 30, 2019 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | This species occurs in at least 18 locations scattered across southern BC (but is expected in many more) with a population size of 2500-10,000 plants. It is not much threatened and appears to do well in disturbed habitats such as cultivated cranberry fields. |
| Range | |
| Range Extent: | D = 1,000-5,000 square km |
| Range Extent Comments: | The current range of Hypericum majus is approximately 3800 square kilometres, extending from Turtle and Spider Lakes on Vancouver Island to Agassiz and Bridal Falls on the Lower Mainland. Discovered along the north shore of the P'end'Oreille River area in 2005 and reported from Shuswap Lake in 1989. Known historically from Sproat Lake, Vancouver Island. |
| Area of Occupancy (km2): | U = Unknown |
| Occurrences & Population | |
| Number of Occurrences: | BC = 6 - 80 |
| Comments: | About 18-19 occurrences are known, but suitable habitats are relatively widespread and additional populations are almost certain to occur. |
| Number of Occurrences with Good Viability / Ecological Integrity: | CD = 4 - 40 |
| Comments: | This species often has a weedy growth habit and occurs in both disturbed and natural habitats. Most of the known occurrences have a very good viability (F. Lomer, pers. comm. 2007). |
| Number of Occurrences Appropriately Protected & Managed: | B = 1 - 3 |
| Comments: | One population occurs within Green Timbers Urban Forest Park and another in Latimer Lake Park. |
| Population Size: | E = 2,500 - 10,000 individuals |
| Comments: | At least 700 plants from field data, but F. Lomer (pers. comm. 2007) estimates 2500-10,000 individuals. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Slightly threatened |
| Comments: | Threats may include urban expansion, hydrologic changes, pesticides, and invasive wetland species such as purple loosestrife (Lythrum salicaria) or reed canarygrass (Phalaris arundinacea), but generally it is not very threatened in BC. Some populations in the lower mainland are threatened but many other locations persist without threats. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | The short-term population trends for Hypericum majus are unknown. They are likely more or less stable. During a boom in cranberry cultivation, they experienced an upward trend, but probably also decreased again (F. Lomer, pers. comm. 2007). |
| Long-Term Trend: | U = Unknown |
| Comments: | The long-term population trends for Hypericum majus are unknown. Habitat trends could be somewhat downward in some portions of the range in the lower mainland, but there are many places that can persist where further development is not likley to occur. This species can persist in disturbed habitats. |
| Other Factors | |
| Intrinsic Vulnerability: | C=Not intrinsically vulnerable |
| Comments: | Hypericum majus has a weedy growth habit. It can tolerate disturbed habitats and is a good seed producer. It does not appear to be intrinsically vulnerable. |
| Environmental Specificity: | D=Broad. Generalist or community with all key requirements common. |
| Comments: | In British Columbia, Hypericum majus grows in habitats that are periodically inundated or are completely submerged during part of the growing season. Known sites include vernal pools, gravelly shorelines and muddy tidal shores in the lowland zone. In addition to natural areas, this taxon has been observed in disturbed or cultivated areas, where it can be quite weedy, such as railroad yards, roadsides, abandoned gravel pits and cultivated cranberry bogs. |
| Other Rank Considerations: | This species hybridizes with H. boreale, however, the offspring are sterile. |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Donovan, M. and J.L. Penny |
| Date: | September 24, 2007 |
| 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. 2007. Conservation Status Report: Hypericum majus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 4, 2026).