Smooth goosefoot (Chenopodium subglabrum) COSEWIC assessment and status report: chapter 2

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Executive Summary

Species information

Smooth goosefoot (Chenopodium subglabrum) is a member of the Chenopodiaceae or goosefoot family. It is a shallow-rooted annual with many ascending, branched stems, 2-8 dm tall. Leaves are alternate, linear, entire, fleshy, one-veined and glabrous (i.e. hairless) or nearly so. The inflorescence is open and leafy with the small, greenish-reddish flowers produced in widely spaced small rounded clusters called glomerules. The calyx (i.e. sepal) lobes are keeled and cover the fruit. There are 2-5 stamens and 2 stigmas. The thin-walled fruit contains one lens-shaped seed that is black and shiny.

Distribution

Smooth goosefoot is restricted to North America and distributed from southern Alberta east to southwestern Manitoba in Canada, and south in the United States to Utah and Colorado.

Habitat

The habitat of smooth goosefoot contains some element of active sand. It is commonly found on the stabilizing edges of active (i.e. moving) dunes as well as dune blowouts, and occasionally on bare or recently disturbed sand plains. It has also been found on river sand bars and sandy floodplain terraces. Commonly associated species include the following: Agropyron dasystachyum, Calamovilfa longifolia, Chenopodium pratericola, Elymus canadensis, Heterotheca villosa, Helianthuspetiolaris, Lygodesmia rostrata, L. juncea, Oryzopsis hymenoides and Psoralealanceolata. Shrub cover often includes: Arctostaphylos uva-ursi, Artemisia cana, Juniperus horizontalis and Salix exigua.

Biology

Smooth goosefoot is a sexually reproducing annual species. It produces fruit and sets seed at most sites. The seeds may remain in the seed bank for several years, waiting for the moist conditions it favours for germination. As this species is able to colonize active sand, it plays a role in dune stabilization. Its seed provides food for small rodents.

Population sizes and trends

This species is rare temporally as well as spatially. In 2004, there was a population explosion of smooth goosefoot in Saskatchewan, possibly triggered by the abundant late summer precipitation. Several thousand plants were observed in Saskatchewan in 1997 and 1998 but in 2004 the population was estimated to be 8,400. The total Alberta population in the late 1980s was several hundred. At the Dominion Sand Hills site less than five plants were seen in 1987 but at least 40 were seen in 2004. In Manitoba, plants were finally observed again in 2004 in the Routledge Sand Hills; the last observation was made 45 years ago. Whether a population boom occurred at other sites in 2004 is unknown but given similar climate conditions all over the prairies it seems likely. The germination of this species is therefore erratic, likely in response to climatic conditions; this makes the overall population trend difficult to determine. The estimated population in Canada is likely between 5,200 and 10,000 individuals.

Limiting factors and threats

The processes of dune stabilization and fire control threaten survival of this species. There has been considerable loss of habitat as dunes become vegetated throughout this species’ range. Some of the plants observed have been noted as being grazed, perhaps by both cattle and wildlife. At several locations, invading exotic weeds may usurp the habitat of smooth goosefoot. Oil and gas development is rapidly expanding in the sand hill complexes of Saskatchewan and may negatively impact this species. Recreational activities in active dune areas may result in the loss of some plants.

Special significance of the species

Smooth goosefoot is at risk nationally and rare in the United States. Due to its ability to colonize active sand it is important ecologically in dune stabilization. A few related species of Chenopodium are useful agriculturally including quinoa (C. quinoa) and good King Henry (C. bonus-henericus).

Existing protection

No specific legal status is accorded smooth goosefoot in any part of Canada. All three provinces where this species occurs have endangered species legislation; however, Alberta’s Wildlife Act currently does not include protection for plants; protective regulations for plants under this Act are being developed. The NatureServe rank is Global G3G4 (vulnerable-apparently secure), Canada N2 (imperiled), Alberta S1 (critically imperiled), Saskatchewan S2 (imperiled), and Manitoba S1 (critically imperiled).

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. On June 5^th 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.

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 for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

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

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.