Beaked spike rush (Eleocharis rostellata)

KingdomPlantae
PhylumTracheophyta
ClassLiliopsida
OrderCyperales
FamilyCyperaceae
GenusEleocharis (1)
SizeLength: 0.4 - 1 m (2)

The beaked spike rush has not yet been classified by the IUCN. 

A stout, robust perennial plant (2) (3), the beaked spike rush (Eleocharis rostellata) has proliferous clustering stems (3) (5), which form distinctive thick tussocks (4). The stems are slender, flattened and leafless (3) (6), with each individual stem ending in a single, cylindrical spike (6) (7). The flowering stems of the beaked spike rush are typically upright (7), while the wiry, non-flowering stems frequently arch downwards, rooting to the ground at the tip to form characteristic dense tufts (4) (5) (6) (7) (8).

The leaves of the beaked spike rush are made up of a grass-like blade and a closed sheath, and are usually arranged in a tuft around the base of the stem (9). The leaf sheaths are generally dark red to brown, becoming increasingly reddish at the tips (8). The small, inconspicuous flowers of the beaked spike rush are arranged in a ‘spikelet’ at the end of the stem (9). Each spikelet contains between 10 and 40 greatly reduced flowers (3) (8), which have very small, dense spines and brownish bristles (8). The blunt, oval-shaped scales of the spikelet are green or brownish, often with a darker vein in the centre of the scale (4) (7).

The beaked spike rush produces a large, single-seeded, greenish to brown fruit, known as an achene, which has a triangular or pyramid-shaped tubercle at the tip (6) (8) (11). The shape of the achene is highly variable (4) (5) (10), and the outer surface of the fruit is typically covered with a network of fine lines (7).

The beaked spike rush occurs primarily in North America, from Vancouver Island to Nova Scotia in Canada, south through the United States to northern Mexico. The beaked spike rush also occurs in the Greater Antilles and the South American Andes (2) (3) (6).

A wetland plant, the beaked spike rush occurs primarily in alkaline habitats such as saline, brackish or calcareous fens and marshes (6) (8) (11). It frequently occurs on tidal flats and along the coast, as well as by stream banks, alkaline seeps, lake margins and around hot springs (2) (3).

The beaked spike rush occurs at elevations of 50 to 2,400 metres (8).

A highly competitive species, the beaked spike rush often forms large single-species stands (8). It flowers from June to August or September, although the exact timing varies with location (2) (3) (6).

The primary threat to the beaked spike rush is the invasion of its habitat by non-native plants, which compete with this species for space and resources (3). The beaked spike rush is also threatened by the development of coastal plains, and by livestock which damage this species’ habitat (2).

There are currently no specific conservation measures targeting the beaked spike rush.

A systematic survey for this species in suitable habitat throughout its range is recommended to help determine its population status (3).

Find out more about the beaked spike rush:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. ITIS (July, 2011)
    http://www.itis.gov/
  2. Carey, J.H. (1994) Eleocharis rostellata. In: Fire Effects Information System (Online). U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Available at:
    http://www.fs.fed.us/database/feis/plants/graminoid/eleros/all.html
  3. Washington State Department of Natural Resources - Beaked spike rush Eleocharis rostellata (July, 2011)
    http://www1.dnr.wa.gov/nhp/refdesk/fguide/pdf/elro.pdf
  4. Coffin, B. and Pfannmuller, L. (1988) Minnesota's Endangered Flora and Fauna. University of Minnesota Press, Minnesota.
  5. Rhoads, A.F. and Block, T.A. (2007) The Plants of Pennsylvania: An Illustrated Manual. University of Pennsylvania Press, Pennsylvania.
  6. Maine Natural Areas Program, Maine Department of Conservation - Beaked spike rush Eleocharis rostellata (July, 2011)
    http://www.maine.gov/doc/nrimc/mnap/features/eleros.htm
  7. Britton, N.L. and Brown, A. (1913) An Illustrated Flora of the Northern United States, Canada and the British Possessions - from Newfoundland to the Parallel of the Southern Boundary of Virginia, and from the Atlantic Ocean westward to the 102D Meridian. Volume 1. Charles Scribner’s Sons, New York.
  8. Flora of North America - Beaked spike rush Eleocharis rostellata (July, 2011)
    http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357785
  9. Heywood, V.H. (1978) Flowering Plants of the World. Oxford University Press, Oxford.
  10. Socorro González-Elizondo, M. and Peterson, P.M. (1997) A classification of and key to the supraspecific taxa in Eleocharis (Cyperaceae). Taxon, 46(3): 433-449.
  11. Herbarium, University of Michigan - Beaked spike rush Eleocharis rostellata (July, 2011)
    http://michiganflora.net/species.aspx?id=1121