USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

61. Juncaceae, the Rush Family

1. Juncus L. -- Rush

9. Juncus ensifolius Wikst.


Rhizomatous perennial 1.5-6 dm tall; culms single or loosely clustered. Leaves 2-4 per culm, the blade folded along the midrib with the margins united, thus laterally flattened and equitant (with one edge toward the culm), 1.5-6 mm wide, incompletely cross-septate; sheaths green or reddish, with broad scarious margins, these often prolonged as low rounded auricles to 0.5 mm long. Inflorescence short to oblong, usually few-branched with the branches erect or nearly so; glomerules (1)2-several (seldom more), hemispheric to subglobose, 5- to many-flowered, to ca. 1 cm across. Flowers dark brown, 3-4 mm long; tepals lanceolate, the outer tepals acuminate, sharp-pointed, the inner ones shorter, acute, scarious-margined; stamens 6(3). Capsules oblong, 1-locular, rounded to the short beak, shorter than to exceeding the tepals; seeds ellipsoid to fusiform, 0.4-0.6 mm long and apiculate at both ends, or sometimes to 1 mm long with a taillike appendage at one or both ends. Jul--Sep. Margins of springs, streams, ponds and in seepage areas at moderate to high elevations; occasional in the Black Hills and with one record from Custer Co., MT; (SD and MT to AK, s to NM, AZ and CA, also Que. and Ont.).

Our plants, with usually 6 stamens and the anthers about equaling the filaments, are assigned to var. montanus (Engelm.) C. L. Hitchc.

GIF- Distribution Map

Map key


Previous Section -- Juncus dudleyi Wieg. -- Dudley's rush
Return to Family -- Juncaceae - The Rush Family
Next Section -- Juncus gerardii Loisel -- Saltmeadow rush

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/vascplnt/species/jens.htm
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:43:47 EST
Sioux Falls, SD [sdww54]