Howell’s triteleia (Triteleia howellii) COSEWIC assessment and status report: chapter 7
Population Sizes and Trends
Triteleia howellii has been collected at 12 sites in Canada, all of which are located on southeastern Vancouver Island (Table 1). Nine of the twelve sites have been confirmed since 1997, while the status of plants at the remaining three sites is unknown and the populations are likely extirpated. Population areas range from small (1 m²) to over three or four hectares, while plant numbers range from a single plant to over 450 plants (Table 1).
The analysis of population trends is prevented by limited demographic data. The sites that have recently been examined show the populations are apparently stable although flowering plants may vary.
| Collection Site | Last Observation | Collector | Population (number/area) |
|---|---|---|---|
| Oak Bay (Victoria) | 1912 | Beaven | Extirpated |
| Uplands (Victoria) | 1917 | Anderson | Extirpated |
| Saanich Arm (Victoria) | 1919 | Newcombe | Extirpated |
| Albert Head (Metchosin) | 1997 | Ussery | 8/2 m² |
| Witty’s Lagoon Regional Park (Metchosin) | 1999 | Douglas & Penny | 43/200 m² |
| Horth Hill Regional Park (North Saanich) | 1999 | Fontaine | 4/3 m² |
| Gordon Head (Saanich) | 1999 | Fontaine | 51/5 m² |
| Somenos Lake, Timbercrest development (Duncan) | 2001 | Douglas | 45/8 m² |
| Cowichan River Estuary (Duncan) | 2001 | Douglas | 62/3 m² |
| Cowichan Bay Garry Oak Nature Park, near Quamichan Lake, (Duncan) | 2001 | Douglas | 450/3-4 ha |
| Beacon Hill Park (Victoria) | 2002 | Ceska | 40/12 m² |
| Thetis Lake Regional Park (View Royal) | 2002 | Ceska | 1/1 m² |
Page details
- Date modified: