Circaea alpina

Tracheophyta MagnoliopsidaOnagraceaeCircaeaCircaea alpina

Ecology

A perennial herb typically associated with seepage areas within rocky, bryophyte-rich Quercus woodland, but also found amongst boulders and scree by the sides of streams and waterfalls, under Pteridium, and even amongst Sphagnum. It probably spreads by rhizomes and stolons, as well as by seed. Generally lowland, but reaching 755 m on Knock Fell (Westmorland).

Status

Native

World Distribution

Circumpolar Boreal-montane element.

Broad Habitats

Broadleaved, mixed and yew woodland

Light (Ellenberg): 4

Moisture (Ellenberg): 7

Reaction (Ellenberg): 5

Nitrogen (Ellenberg): 5

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 2.2

July Mean Temperature (Celsius): 13

Annual Precipitation (mm): 1836

Life form information

Height (cm): 30

Perennation - primary

Perennial

Life Form - primary

Non-bulbous geophyte (rhizome, corm or tuber)

Woodiness

Herbaceous

Clonality - primary

Rhizome far-creeping

Count of 10km squares in Great Britain: 40

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: 0.48

Distribution information

JNCC Designations

NBNSYS0000003606

Scarce Atlas Account

Scarce Atlas Account: 

Circaea alpina L.

Alpine enchanter's-nightshade

Status: scarce

 

 

A small, delicate, inconspicuous plant of open and usually shaded or north-facing seepage areas and streamsides. In the Lake District it is characteristic of rocky, bryophyte-rich submontane Quercus petraea woodland, where it is often associated with C. x intermedia and Chrysosplenium oppositifolium. Here, as on Arran, it also occurs on open hillsides in block scree, among boulders by the sides of streams and by waterfalls, also under bracken and even amongst sphagnum. It descends virtually to sea-level on Arran. All sites are below 400 metres except one at 750 metres in a limestone sinkhole near Cross Fell. 

The main method of reproduction is probably by rhizome. It does, however, fruit freely, the flowers being self-pollinated.

Its status and distribution in the British Isles were considerably clarified by Raven (1963). There has been much confusion in the past between C. alpina and the much commoner sterile hybrid C. x intermedia and this confusion unfortunately still persists. The extremely restricted and relict distribution of C. alpina is in marked contrast to the present wide distribution of C. x intermedia. This is probably the result both of the decrease of C. alpina, perhaps due to competition from C. x intermedia, and the increase of the latter with its more vigorous vegetative propagation.

C. alpina is represented in Europe only by subsp. alpina. This has a wide distribution throughout the northern boreal zone, being most frequent in the mountains of central and northern Europe, eastern North America and Japan. Other subspecies occur in Asia and western North America.

 

G. Halliday

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.