A strong, rhizomatous perennial herb growing in dense stands in fens, marshes, wet meadows, ditches and by water, usually in more base-rich conditions than any of the other jointed-rushes (sect. Septati); it also sometimes occurs in brackish water. Lowland.
J. subnodulosus has been lost from many sites in S. England both before 1930 and subsequently, because of drainage of its habitat. However, it is now known to be more frequent in Wales than was suspected. This species is very distinct from other jointed-rushes and the map should indicate its true distribution.
European Southern-temperate element.
Light (Ellenberg): 8
Moisture (Ellenberg): 9
Reaction (Ellenberg): 8
Nitrogen (Ellenberg): 4
Salt Tolerance (Ellenberg): 0
January Mean Temperature (Celsius): 3.9
July Mean Temperature (Celsius): 15.5
Annual Precipitation (mm): 838
Height (cm): 120
Perennation - primary
Life Form - primary
Clonality - primary
Count of 10km squares in Great Britain: 680
Count of 10km squares in Ireland: 224
Count of 10km squares in the Channel Isles: 2
Atlas Change Index: 0.15
Weighted Changed Factor: 0
Weighted Change Factor Confidence (90%)
Atlas text references
1986. Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
1965. Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
Richards & Clapham (1941e)