Juncus triglumis

Tracheophyta MagnoliopsidaJuncaceaeJuncusJuncus triglumis


A short, tufted, montane perennial herb of base-rich damp rocky or gravelly places, flushes and small marshes with little competing vegetation. It occupies the same habitats as the rarer J. biglumis, and often grows near or with it, but is less restricted to high altitudes, descending from 1065 m on Snowdon (Caerns.) to, formerly, 60 m in Shetland.



World Distribution

Circumpolar Arctic-montane element.

© Pete Stroh

Broad Habitats

Light (Ellenberg): 8

Moisture (Ellenberg): 9

Reaction (Ellenberg): 6

Nitrogen (Ellenberg): 2


Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 0.9

July Mean Temperature (Celsius): 11.8

Annual Precipitation (mm): 2085

Life form information

Height (cm): 20

Perennation - primary


Life Form - primary




Clonality - primary

Tussock-forming graminoid, may slowly spread

Count of 10km squares in Great Britain: 200

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.38

Distribution information

JNCC Designations


PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.

Atlas text references