Calamagrostis stricta

Tracheophyta MagnoliopsidaPoaceaeCalamagrostisCalamagrostis stricta


A tufted rhizomatous perennial herb of near-neutral mires and lake margins. 0-340 m (Kingside Loch, Selkirks.).



World Distribution

Circumpolar Boreo-arctic Montane element.

Broad Habitats

Fen, marsh and swamp (not wooded)

Light (Ellenberg): 9

Moisture (Ellenberg): 9

Reaction (Ellenberg): 4

Nitrogen (Ellenberg): 2

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 2.9

July Mean Temperature (Celsius): 14.2

Annual Precipitation (mm): 928

Height (cm): 100

Perennation - primary


Life Form - primary




Clonality - primary

Rhizome shortly creeping

Count of 10km squares in Great Britain: 22

Count of 10km squares in Ireland: 6

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.74

JNCC Designations


Scarce Atlas Account

Scarce Atlas Account: 

Calamagrostis stricta (Timm) Koeler

Narrow small-reed

Status: rare?


A plant of near-neutral bogs and marshes. At a site near Dalmellington it grows with Deschampsia cespitosa, Filipendula ulmaria, Juncus effusus and Phalaris arundinacea. In Yorkshire it is found as an emergent at the edge of the Leven Canal. It is primarily a lowland species, but ascends to 340 metres at Kingside Loch.

C. stricta is a tufted perennial, with slender creeping rhizomes. It flowers in June and July. Little is known of its reproductive biology.

It is difficult to assess trends in the distribution of C. stricta as it has previously been confused with C. scotica, C. purpurea and hybrids with C. canescens and perhaps with other species. It has certainly been lost from some sites through drainage.

C. stricta has a circumpolar distribution. It is widespread in the boreal zone of Europe, Asia and North America, and occurs very locally in mountains further south.

British populations of C. stricta are variable, perhaps because of past hybridisation and introgression with other species (Stace 1975). Where C. stricta grows with C. scotica in Caithness there is little sign of hybridisation between them, but some plants in populations of C. stricta in Selkirkshire show some similarity to C. scotica although they are well outside the southern limit of that species.

As this species has been recorded in only 15 of the British 10 km squares since 1970, it qualifies for inclusion in the Red Data Book (Perring & Farrell 1983) under the current criteria. However it will probably be recorded in more than 15 British 10 km squares, when, as seems likely, it is refound in some of its old localities.


O. M. Stewart

Atlas text references

References: Atlas (397b)
Crackles (1995
Curtis TGF, McGough HN
1988.  The Irish Red Data Book. 1. Vascular Plants.
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Meusel H, Jäger E, Weinert E
1965.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 1. 2 vols.
Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain.
Wigginton MJ
1999.  British Red Data Books. 1. Vascular plants, edn 3.