Fragrant popcornflower (Plagiobothrys figuratus) COSEWIC assessment and status report: chapter 11

Technical Summary

Plagiobothrys figuratus

Fragrant popcornflower – plagiobothryde odorante

Range of Occurrence in Canada:

South western British Columbia

Demographic Information

Generation time (average age of parents in the population)

<1 yrs

Population trend and dynamics

Percentage of reduction in total number of mature individuals over the last

>50 %

Percentage of reduction in total number of mature individuals over the next

Unknown

Percentage reduction in total number of mature individuals over any  period, over a time period including both the past and the future.

Unknown

Are the causes of the decline clearly reversible?

No

Are the causes of the decline clearly understood?

Unknown

Are the causes of the decline clearly ceased?

No

Observed trend in number of populations

Decline

Are there extreme fluctuations in number of mature individuals?

Unknown but likely

Are there extreme fluctuations in number of populations?

No

Number of mature individuals in each population

Hornby Island

1 in 2005
0 in 2006
Grand Total: Only seed bank present?

Extent and Area Information

Estimated extent of occurrence (km²)

Historical: area of acute triangle formed by Victoria, Hornby Island and Comox. Historical:1600. Present: <1 km²

Observed trend in extent of occurrence

Decline

Are there extreme fluctuations in extent of occurrence?

No

Estimated area of occupancy (km²)

Actual area occupied is about 1 square m but AO based on a 1x1 km grid is 1 square km : 1 km²

Observed trend in area of occupancy :

Unknown but likely a decline

Are there extreme fluctuations in area of occupancy?

No

Is the total population severely fragmented?

No

Number of current locations :

1

Trend in number of locations

Decline

Are there extreme fluctuations in number of locations?

No

Observed trend in of habitat

Decline

Quantitative Analysis

[0.00% probability of extirpation in years]

Threats (actual or imminent, to populations or habitats)

  • loss of habitat due to urbanization/development
  • environmental stochasticity
  • demographic stochasticity
  • inbreeding depression
  • competition from native and alien plant species

Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: (G4N4)

Is immigration known or possible?

Unknown

Would immigrants be adapted to survive in Canada?

Likely

Is there sufficient habitat for immigrants in Canada?

Some habitat is available but limited. Likely

Is rescue from outside populations likely?

No

Current Status

COSEWIC: Endangered 2008

Status and Reasons for Designation

Status: Endangered

Alpha-numeric code: B1ab(iii)+ 2ab(iii); C2a(i,ii); D1

Reasons for Designation: Although only a single plant was seen in 2005 and none in 2006, the species is likely extant in the form of seeds in the soil. The species’ potential for continued survival is at risk from ongoing threats to its habitat from such factors as loss of habitat due to urbanization/development, environmental and demographic stochasticity, and competition from native and alien plant species.

Applicability of Criteria

  • Criterion A: (Decline in Total Number of Mature Individuals): Not applicable. Population likely fluctuates.
  • Criterion B: (Small Distribution Range and Decline or Fluctuation): Endangered B1ab(iii)+2ab(iii); EO and AO below maximum limits with only a single population potentially present in the form of a soil seed bank; a continuing decline is inferred based on the presence of ongoing threats to habitat quality of this site located adjacent to a roadside and near a housing development.
  • Criterion C: (Small and Declining Number of Mature Individuals): Endangered C2a(i,ii); &lt;2500 mature plants with continuing decline inferred due to ongoing threats to habitat at a single population with &lt;250 mature individuals.
  • Criterion D: (Very Small Population or Restricted Distribution): Endangered D1 with &lt;250 mature individuals.
  • Criterion E: (Quantitative Analysis): None available

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