Van brunt’s jacob’s-ladder (Polemonium vanbruntiae) COSEWIC assessment and status report: chapter 2

Executive Summary

Van Brunt’s Jacob’s-ladde
Polemonium vanbruntiae

Information on the species

Van Brunt’s Jacob’s-ladder (Polemonium vanbruntiae) is an herbaceous perennial of the Polemoniaceae. The stems are upright, 40 to 140 cm tall. The leaves are composed of 7 to 21 ovate to oblong leaflets. The panicled flowers, which are blue-violet in colour, are 15 to 25 mm in diameter and have 5 petals and 5 sepals; the stamens are yellow and strongly exserted. The fruit is an ovoid capsule containing brownish-black seeds.

Distribution

Van Brunt’s Jacob’s-ladder is endemic to the central Appalachians. It is found from West Virginia to the southernmost part of Quebec and eastern Maine. In Canada, this species is only known to occur in the Eastern Townships and Bois-Francs regions of Quebec, at the bottom of the Nicolet and Stoke River valleys. There is also a historic record for New Brunswick.

Habitat

This plant is found in moist habitats such as riparian alder thickets, wet clearings, riparian herbaceous meadows and old fields with sufficient moisture. These are open or semi-open habitats, subject to flooding in the spring, with rich soils, often located near the bottom of slopes or near streams. This montane species occurs in rather cool microclimates.

Biology

The species reproduces by seed or by rhizomes (vegetatively). The flowers are pollinated by a wide variety of insects, mainly honey bees and bumblebees. Seed germination occurs only after a period of cold, dry conditions.

Population sizes and trends

Currently, there are only 8 known Canadian populations, all found in Quebec, for a total of approximately 20,000 plants. Although two new populations were discovered in Quebec in 2001, two other populations are considered to have disappeared, and the species is declining both in its extent of occurrence and its area of occupancy.

Limiting factors and threats

Encroachment by the farming and logging industries represents the main limiting factor and threat to Van Brunt’s Jacob’s-ladder. These industries have caused the decline or extirpation of some populations. Road construction and other projects altering drainage can also be detrimental, if they cause prolonged flooding or drying-up of the habitat.

Special significance of the species

Van Brunt’s Jacob’s-ladder is the only species of genus Polemonium that is native to Canada east of Alberta. It is rare and sporadic over its entire range. It has primitive characteristics and may be a relict species. Its great beauty gives the species a horticultural potential for wetland gardens.

Existing protection or other status designations

This plant is not found on any Canadian protected public land. However, an important site has just been purchased by a private conservation agency, and negotiations are either under way or planned for the purchase of other sites by the same agency. The species has been designated threatened in both Canada and Quebec, where it falls under the provincial Threatened or Vulnerable Species Act.

Summary of the status report

Although Polemonium vanbruntiae is threatened in Canada and is generally on the decline, new populations have been discovered recently, and potential sites still need to be explored. Moreover, conservation measures have recently begun to take shape, and they should, at the very least, stabilize the status of this species.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) determines the national status of wild species, subspecies, varieties, and nationally significant populations that are considered to be at risk in Canada. Designations are made on all native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fish, lepidopterans, molluscs, vascular plants, lichens, and mosses.

COSEWIC Membership

COSEWIC comprises representatives from each provincial and territorial government wildlife agency, four federal agencies (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biosystematic Partnership), three nonjurisdictional members and the co-chairs of the species specialist groups. The committee meets to consider status reports on candidate species. 

Definitions

Species
Any indigenous species, subspecies, variety, or geographically defined 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) Footnote1
A species of special concern because of characteristics that make it particularly sensitive to human activities or natural events.

Not at Risk (NAR) Footnote2
A species that has been evaluated and found to be not at risk.

Data Deficient (DD)*** Footnote3
A species for which there is insufficient scientific information to support status designation.

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. Species designated at meetings of the full committee are added to the list.

Canadian Wildlife Service

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

 

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