Branched bartonia (ssp. paniculata) COSEWIC assessment and status report: chapter 12

Technical Summary

Bartonia paniculata  ssp. paniculata

Branched Bartonia – bartonie paniculée

Range of Occurrence in Canada:

Ontario

Extent and Area Information

Extent of occurrence (EO)(km²)
Based on polygon around sites. 400 km²
Specify trend in EO :
Stable
Are there extreme fluctuations in EO? :
No
Area of occupancy (AO) (km²)
Based on area of bogs-fens at the sites. <1 km²
Specify trend in AO :
Stable
Are there extreme fluctuations in AO?
No
Number of known or inferred current locations :
6
Specify trend in # :
Unknown
Are there extreme fluctuations in number of locations?
No
Specify trend in area, extent or quality of habitat :
Stable

Population Information

Generation time (average age of parents in the population) :
1 year
Number of mature individuals :
Perhaps 500-1000 (the upper value is highly speculative)
Total population trend:
Unknown
% decline over the last/next 10 years or 3 generations.
N/A
Are there extreme fluctuations in number of mature individuals?
Unknown
Is the total population severely fragmented?
Yes
Specify trend in number of populations :
Stable
Are there extreme fluctuations in number of populations?
No
List populations with number of mature individuals in each:
See table 1

Threats (actual or imminent threats to populations or habitats)

  • invasive shrubs at two sites represent the most serious threats
  • potential rail line reconstruction

Rescue Effect (immigration from an outside source)

Status of outside population(s)?
USA: Secure
Is immigration known or possible?
Unlikely
Would immigrants be adapted to survive in Canada?
Unknown
Is there sufficient habitat for immigrants in Canada?
Possibly
Is rescue from outside populations likely?
Unlikely

Quantitative Analysis

N/A

Current Status

COSEWIC: Threatened

Status and Reasons for Designation

Status: Threatened  

Alpha-numeric code: Met criteria for Endangered, B1ab(iii)+2ab(iii); C2a(i), because it is not at imminent risk of extirpation.

Reasons for Designation: A cryptic wetland annual species of Atlantic Coastal Plain affinity, highly restricted both geographically and ecologically and present at only six of seven documented sites. Ontario populations are disjunct by about 600 km from the main range of the species with little potential for a rescue effect. The greatest potential risk is from the invasive shrub, glossy buckthorn, at two localities.

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