Poa alpina

Tracheophyta MagnoliopsidaPoaceaePoaPoa alpina

Ecology

A perennial herb of damp mountain rock faces, open ledges and rocky slopes on calcareous substrates, often with P. glauca. Most populations are wholly or partially proliferous. From 580 m at High Cup Nick (Westmorland) to 1190 m on Aonach Beag (Westerness).

Status

Native

World Distribution

Circumpolar Arctic-montane element, with a disjunct distribution.

© Pete Stroh

Broad Habitats

Montane habitats (acid grassland and heath with montane species)

Light (Ellenberg): 7

Moisture (Ellenberg): 5

Reaction (Ellenberg): 7

Nitrogen (Ellenberg): 3

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 0.6

July Mean Temperature (Celsius): 11.5

Annual Precipitation (mm): 2142

Height (cm): 40

Perennation - primary

Perennial

Life Form - primary

Hemicryptophyte

Woodiness

Herbaceous

Clonality - primary

Tussock-forming graminoid, may slowly spread

Clonality - secondary

Detaching ramets on inflorescence

Count of 10km squares in Great Britain: 72

Count of 10km squares in Ireland: 2

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: -0.31

JNCC Designations

NBNSYS0000002547

Scarce Atlas Account

Scarce Atlas Account: 

Poa alpina L.

Alpine meadow-grass

Status: scarce

 

This montane grass usually grows in scattered small tufts on steep, open faces of calcareous rock, and its distribution is inevitably limited to the richer mountains, especially the calcareous schist formations of the central Scottish Highlands. Even here it could seldom be described as abundant. Some outlying populations are very small, and the plant is absent from a good many suitable habitats. Its open rock face associates include Carex atrata, Cerastium alpinum, Draba incana, Poa glauca, Saxifraga oppositifolia, S. nivalis, Silene acaulis and a range of mosses. This grass also grows sparingly in alpine/dwarf-herb swards and moss carpets on base­-rich soils, where competition is slight. The altitudinal range is from 580 metres at Maize Beck up to 1140 metres on Bidean nan Bian in Glen Coe.

This is a perennial grass. Most British populations are viviparous, but seed-bearing forms are widespread and there is no particular pattern of occurrence for either. Spread by either mode is probably very limited under present conditions. 

The potential habitat for P. alpina is probably greater than that which it currently occupies, and the species may be restricted by grazing, In Norway it is not confined to cliffs in areas in which grazing is light. It has also suffered from collecting in some outlying British localities, but most of the populations recorded before 1970 are probably still extant.

This is an arctic-alpine species with a wide circumpolar distribution.

 

D. A. Ratcliffe

Atlas text references

Atlas (380a)
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.