BC Conservation Data Centre: Conservation Status Report
Lysimachia minima
chaffweed
| Scientific Name: | Lysimachia minima |
|---|---|
| Scientific Name Synonyms: |
Anagallis minima
Centunculus minimus |
| English Name: | chaffweed |
| Provincial Status Summary | |
| Status: | S4 |
| Date Status Assigned: | March 31, 2018 |
| Date Last Reviewed: | April 30, 2019 |
| Reasons: | There are 34 extant occurrences of this species in BC. and it is expected to occur in more locations than are currently known. The estimated range extent (including areas of open ocean) is 97,500 square km and the area of occupancy is 100 square km. Since 1999, this species has been discovered in man-made habitats in at least six locations in the Greater Vancouver area, where it is believed to have been introduced into habitats within which it did not previously exist. |
| Range | |
| Range Extent: | F = 20,000-200,000 square km |
| Range Extent Comments: | Chaffweed has been found from the north coast, south to Trial Island near Victoria, west to Port Alberni and east into the interior of the South Okanagan. The estimated extent of occurrence (including areas of open ocean) is 97,500 square kilometres, calculated using GIS tools (R. Batten, pers. comm.). |
| Area of Occupancy (km2): | E = 26-125 |
| Area of Occupancy Comments: | The estimated area of occupany is 100 square km, or 25 - 4 square km grid cells (R. Batten, pers. comm.). |
| Occurrences & Population | |
| Number of Occurrences: | C = 21 - 80 |
| Comments: | There are 34 extant and 8 historical populations known . Additional populations of chaffweed are likely as it may be under-collected given its small size, tiny nondescript flowers and sometimes ephemeral habitat. The species may disappear for years only to reappear as it springs back in the soil seed bank during favorable years (C. Bjork pers. comm.). One population near Victoria was extirpated by road construction. |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Percent Area with Good Viability / Ecological Integrity: | U = Unknown |
| Comments: | Many occurrences have insufficient information to assess viability. |
| Number of Occurrences Appropriately Protected & Managed: | B = 1 - 3 |
| Comments: | At least 3 populations are in protected areas including Trial Island Ecological Reserve, Helliwell Provincial Park and South Texada Island Provincial Park. |
| Population Size: | U = Unknown |
| Comments: | Because chaffweed is an annual species, population size will fluctuate annually depending on environmental conditions. At least 3,000 plants were reported from 5 occurrences. The other observations are lacking population data. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | D = Low |
| Comments: | Current threats include competition from invasive plants, wetland disturbance and changes to the hydrologic regime. The population southeast of Freeman King Regional Park was extirpated by road construction and the area is now covered with rock fill. However, this species has a strong ability to establish itself in a wide variety of habitats, suggesting some resilience to threats. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Comments: | Habitat trends on southeastern Vancouver Island and the Gulf Islands are likely declining. Population trends are unknown. but are likely mostly stable. One population near Freeman King Regional Park was lost to road construction. |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | C=Not intrinsically vulnerable |
| Comments: | Chaffweed is not known to be intrinsically vulnerable, but this species may be more resilient than once thought. |
| Environmental Specificity: | CD = Moderate to broad. |
| Comments: | Chaffweed is found in salt marshes, in vernal pools and on pond margins in the lowland zone of southern Vancouver Island and the Gulf Islands, where it is believed to be a native species. In the Fraser Valley, this species is believed to be a recent introduction as it had not been collected in the area before 1999. It has been found at six locations in the Greater Vancouver area and all sites were man-made habitats such as cranberry bogs, sand dredgings, disturbed peaty road clearings, gravelly roadside depressions, cleared moist gravel flats and wet field pools. Chafweed has a global distribution, a strong ability to establish itself in a wide variety of habitats and appears to be spreading, possibly by birds (F. Lomer, pers. comm. 2008). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | Studies are needed to ascertain the native status of populations on southern Vancouver Island and the Gulf Islands. This species could be expected in B.C. following similar patterns observed for other native species on southern Vancouver Island. |
| Inventory Needs: | |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Donovan, M. |
| Date: | April 20, 2018 |
| 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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Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp.
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Lea, E. 2002. Historical Garry Oak ecosystems of Greater Victoria and the Saanich Peninsula. 1:20,000 scale maps. Prepared for Garry Oak Ecosystems Recovery Team by Terrestrial Inf. Branch, B.C. Minist. Sustainable Resour. Manage., Victoria.
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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. 2018. Conservation Status Report: Lysimachia minima. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).