Species Profile

Bent Spike-rush Southern Mountain population

Scientific Name: Eleocharis geniculata
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: April 2009
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered


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Quick Links: | Description | Habitat | Biology | Threats | Protection | National Recovery Program | Documents

Image of Bent Spike-rush

Description

Bent Spike–rush (Eleocharis geniculata) is a small, tufted annual sedge composed of numerous slender stalks (culms). Stalks are usually terminated by a single spikelet composed of bisexual flowers that produce black achenes (small dry fruitlets). Each achene is tipped with a flat and fairly wide tubercle. The black achenes separate this species from most other tufted Canadian species of Eleocharis. Until recently, collections of this species from Osoyoos Lake, British Columbia, had been identified as the Purple Spike–rush (E. atropurpurea), but research has shown this to be in error. (Updated 2017/05/25)

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Distribution and Population

Bent Spike–rush is a pantropical species and is fairly widespread in the southern parts of North America. In Canada, ithas been reported from one location in British Columbia (on Osoyoos Indian Band property on the east shore of Osoyoos Lake) and from three sites in south–western Ontario along the northern shore of Lake Erie: Long Point National Wildlife Area, Cedar Springs, and at an historical site in Rondeau Provincial Park. Two designatable units (DU) are considered in this report: the Southern Mountain DU (British Columbia) and the Great Lakes Plains DU (Ontario). The total estimated area of habitat occupied in Canada is 1200 m2 in BC and 2000 m2 in Ontario. The Index of Area of Occupancy based on a 2x2 km grid is 16 km2 (4 km in BC and 12 km2 in ON). (Updated 2017/05/25)

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Habitat

In British Columbia, Bent Spike–rush has been found on soil at the edges of open ephemeral pond wetland complexes within the Bunchgrass Biogeoclimatic Zone. These ponds are flooded throughout much of the year, usually drying during the spring and summer, although sometimes they flood again in late summer. In Ontario, this species is found on wet, sandy to muddy soil in open flats on or along the edges of ephemeral ponds and wet meadows in the Deciduous Forest Region (Carolinian Zone). The Cedar Springs site appears to be an old sandpit. In British Columbia, the species’ habitat appears stable, but in Ontario the habitat is threatened by extensive invasions of the exotic strain of Common Reed (Phragmites australis). (Updated 2017/05/25)

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Biology

Bent Spike–rush grows each year from overwintering achenes. Plants grow into early autumn and produce flowers and achenes, then wither and die during the onset of winter. Not all achenes that are produced germinate the following year. Some remain dormant, sometimes for many years, as a seedbank in the soil. Bent Spike–rush depends on a seedbank for its long–term persistence. Annual plants often have wide fluctuations in plant size and numbers, and the numbers of flowers and achenes produced from year to year. Dispersal is through movement of achenes as there is no means of asexual reproduction in this species. (Updated 2017/05/25)

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Threats

The main natural limiting factor across the Canadian range of Bent Spike–rush is its restriction to a rather specific and geographically limited habitat. In British Columbia, trampling and soil disturbance by cattle and horses, human–related disturbances, invasive plants, especially grasses, and artificial management of the water levels of Lake Osoyoos are threats. The greatest threat to populations in Ontario is the rapid invasion of known and potential habitat by Common Reed. (Updated 2017/05/25)

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Protection

Federal Protection

The Bent Spike-rush, Southern Mountain population, is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

The Southern Mountain population of Bent Spike-rush is not protected by any provincial legislation in British Columbia. However, it is protected within a fenced area by the Osoyoos Indian Band.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Documents

PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

8 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Status Report on the Bent Spike-rush Eleocharis geniculata in Canada (2009)

    Bent Spike-rush (Eleocharis geniculata) is a small, tufted annual sedge composed of numerous slender stalks (culms). Stalks are usually terminated by a single spikelet composed of bisexual flowers that produce black achenes (small dry fruitlets). Each achene is tipped with a flat and fairly wide tubercle. The black achenes separate this species from most other tufted Canadian species of Eleocharis. Until recently, collections of this species from Osoyoos Lake, British Columbia, had been identified as the Purple Spike-rush (E. atropurpurea), but research has shown this to be in error.

COSEWIC Assessments

  • COSEWIC Assessment - Bent Spike-rush (2009)

    Bent Spike-rush (Eleocharis geniculata) is a small, tufted annual sedge composed of numerous slender stalks (culms). Stalks are usually terminated by a single spikelet composed of bisexual flowers that produce black achenes (small dry fruitlets). Each achene is tipped with a flat and fairly wide tubercle. The black achenes separate this species from most other tufted Canadian species of Eleocharis. Until recently, collections of this species from Osoyoos Lake, British Columbia, had been identified as the Purple Spike-rush (E. atropurpurea), but research has shown this to be in error.

Response Statements

  • Response Statement - Bent Spike-rush, Southern Mountain population (2009)

    Only a single population of this annual species of the sedge family is known from a seasonally flooded wetland complex within a sandy spit at Osoyoos Lake, BC. Approximately 10,000 small plants are restricted to an area of about 1200 square metres where they are at risk from stochastic events and the potential impacts from the spread of exotic grasses.

Orders

  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2010)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, hereby acknowledges receipt, on the making of this Order, of the Committee on the Status of Endangered Wildlife in Canada’s (COSEWIC) assessments under subsection 23(1) of the Species at Risk Act with respect to the species set out in the annexed schedule.
  • Order Amending Schedule 1 to the Species at Risk Act (2011)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2009 (2009)

    2009 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species, December 2009 (2009)

    As part of its strategy for protecting wildlife species at risk, the Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, also called the List of Wildlife Species at Risk. Please submit your comments by March 1, 2010 for species undergoing normal consultations and by March 1, 2011 for species undergoing extended consultations.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update March 31, 2017