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 ) 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.

Table 1. Locations and Population Sizes for Triteleia howellii on southeastern Vancouver Island, British Columbia.
Collection Site Last Observation Collector Population
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: