Stoloniferous pussytoes (Antennaria flagellaris) COSEWIC assessment and status report: chapter 2

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COSEWIC Executive Summary

Species information

Antennaria flagellaris was first recorded in the literature in Canadain 1998. Antennaria flagellaris is a stoloniferous, short-lived perennial from a fibrous root. The stolons are up to 10 cm long while the few central flowering stems are up to 3.5 cm tall. It has numerous silky woolly-hairy basal leaves and few stem leaves. The flower heads are terminal with involucres of two types: female and male. Fruits are achenes.

Distribution

In Canada, A. flagellaris is known only from the Similkameen River valley, south of Princeton in southwestern British Columbia.Antennaria flagellaris ranges from southwestern British Columbia, south in the western United States to Idaho, Wyoming Nevada and California. The nearest known occurrence to the BC population is in central Washington, on the Natches River about 190 km to the south.

Habitat

Antennaria flagellarisoccurs inArtemisia tridentata (big sagebrush) shrub/grassland with scattered Pinus ponderosa (Ponderosa pine) and Pseudotsuga menziesii(Douglas-fir) in calcareous, gravelly-clay soils or gravelly sands on eroded, unstable, 20-30% slopes with open southerly aspects. The sites are restricted to the Roany soil series and are characterized by ephemeral seepage. They are saturated by underground water in the winter and dry up in the summer. Non-native species are not present.

Biology

Antennaria flagellaris is a short-lived perennial, dioecious (male and female structures on separate plants), and wind-pollinated. The achenes contain a single seed and numerous hair-like bristles when mature facilitating the wind dispersal. Seeds are produced sexually by out-crossing. This species also reproduces vegetatively by producing stolons that terminate in plantlets.

Population sizes and trends

There are three occurrences ofAntennaria flagellaris in the Similkameen River valley, southwest of Princeton, British Columbia. These populations occur over a distance of 3.2 km and in an occupied area of about 2200 m² with approximately 1,000,000 plants.

Limiting factors and threats

The three populations occur on two private properties in the Agricultural Land Reserve (ALR). The populations occur within 5 km of the town of Princeton, which has seen an increase in housing starts recently. It is quite conceivable that the properties could be removed from the ALR in the future. The roany soil series that occurs in the area produces a landscape with limited suitability to agriculture, which could facilitate removing the land from ALR. In recent years many tracts of ALR land in southern British Columbia have been converted to housing developments, shopping malls and golf courses. Development may be imminent. Currently some of the activities that are permitted in the land reserve may also not be consistent with the persistence of this species. Any developments that even slightly change groundwater levels could be devastating to this taxon. Proposed production of coalbed methane within the region could impact ground water hydrology. Evidence of off-road recreational vehicle use has been observed in close proximity of populations. This activity could alter habitat conditions radically enough to make it inhospitable for A. flagellaris and suitable for weedy species.

Special significance of the species

The calcareous clay, seepage slopes where A. flagellarisoccurs areunique in the Princeton area. In addition, they are not invaded by introductions resulting in a habitat in relatively pristine condition. Furthermore, the populations are unique as they are at the northern extent of their geographic range. Peripheral populations are often genetically and morphologically divergent from central populations and may have an evolutionary and ecological significance important to the species.

Existing protection or other status designations

Provincially, A. flagellaris has been ranked by the Conservation Data Centre as S1 (critically imperiled) and appears on the British Columbia Ministry of Sustainable Resource Management red list, the most critical rank. There is currently no specific endangered species legislation in place for the protection of vascular plants in British Columbia that have been given this critical rank. The populations may be afforded some protection against certain types of property development because they occur in the Agricultural Land Reserve, where the primary use is agriculture. Intensive uses are not prohibited and could be inconsistent with the habitat requirements of A. flagellaris.

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed  under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species and include the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal organizations (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biosystematic Partnership, chaired by the Canadian Museum of Nature), three nonjurisdictional members and the co-chairs of the species specialist and the Aboriginal Traditional Knowledge subcommittees. The committee meets to consider status reports on candidate species.

Definitions (after May 2004)

Species

Any indigenous species, subspecies, variety, or geographically or genetically distinct population of wild fauna and flora.

Extinct (X)

A species that no longer exists.

Extirpated (XT)

A species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A species facing imminent extirpation or extinction.

Threatened (T)

A species likely to become endangered if limiting factors are not reversed.

Special Concern (SC) *

A species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at Risk (NAR)**

A species that has been evaluated and found to be not at risk.

Data Deficient (DD)***

A species for which there is insufficient scientific information to support status designation.

* Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.
** Formerly described as “Not In Any Category”, or “No Designation Required.”
*** Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” (insufficient scientific information on which to base a designation) prior to 1994.

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.