Streambank lupine (Lupinus rivularis) COSEWIC assessment and status report: chapter 2

Executive Summary

Streambank Lupine

Lupinus rivularis

Species Information

Lupinus rivularis Dougl. ex. Lindl. (streambank lupine) is a particularly beautiful species of lupine that stands between 4 and 6 dm. It has an erect habit and lovely lavender flowers that bloom from May until September. While taxonomy and nomenclature for North American lupines is particularly confusing, this species is readily identifiable, particularly when adding features of habitat and elevation to morphological features. It can be separated readily from other lupines in our area by a combination of delicate leaves, erect habit, and early flowering, and by its occurrence at low elevations.

Distribution

Globally, Lupinus rivularis is found only along the Pacific Coast, from northwestern California to southwestern British Columbia. To date in British Columbia, it has been confirmed only in the extreme southwestern corner of the province, with a single population on southern Vancouver Island, and five populations in the lower Fraser Valley. 

Habitat

This speciesoccupies open sandy or gravelly, moist riverbank sites at low elevations proximal to the coast. These are generally sites with little ground cover, though it occasionally occurs under an open canopy. Sites are generally flood prone and, prior to dyking, would have flooded with some regularity. Like other lupines, L. rivularis displays a preference for disturbed, though not weedy, sites.

Biology

Lupinus rivularis is a perennial, primarily herbaceous species, with a long taproot. It is a nodulated species of impoverished sites. Hybridization, a common feature of North American lupines, is reported in this species, and includes hybridization with the invasive L. arboreus (yellow bush lupine), as well as other native lupines (e.g., L. littoralis, seashore lupine). Like other lupine species, it appears to produce abundant amounts of large heavy seeds that can be thrown up to 26 feet from the parent plant when the pods explode.

Population sizes and trends

Only six natural populations of Lupinus rivularis have been confirmed in Canada and British Columbia. Present populations range from 100 plants at one station to only one plant at another station. All populations reported in the Fraser Valley in the late 1980s and early 1990s are still extant. It is speculated that the species might have been more widespread prior to the industrial development and extensive dyking of its riverbank habitat in the coastal reaches of the lower Fraser Valley.

Limiting factors and threats

Lupinus rivularis is a species that occurs at the extreme northern limit of a fairly restricted global range along the Pacific Coast. This may indicate that the species was initially rare in our region and is sensitive to climatic fluctuations. It is also limited in occurrence to a narrow band of habitat along creeks and riverbanks within this range. This is habitat that has been substantially altered by extensive dyking of the river systems in the lower Fraser Valley, as well as by industrial development in floodplain sites that may originally have provided more extensive habitat for the species. Habitat loss for this species is thought to be significant.

Several factors threaten the continued survival of this species both in Canada and throughout its US range, including hybridization and genetic swamping by Lupinus arboreus. Predation by invasive invertebrates poses a threat. Ground maintenance in several sites, including herbicide spraying, also poses extreme threat to our populations. In addition, this particularly beautiful lupine is threatened by wildflower collecting by the general public--as we have witnessed--and is now advertised for use in herbal essences.

Special significance of the species

It is possible that our populations of Lupinus rivularis represent some of the most “pure” populations that remain for this species throughout its range, potentially making our populations highly significant. Further investigation is required here. In addition, the growing interest in lupines as a food crop indicates that preserving as many species’ gene pools as possible may be important agriculturally.

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)*
A species of special concern because of characteristics that make it particularly sensitive to human activities or natural events.

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 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.

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

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