Linnaea borealis

Tracheophyta MagnoliopsidaCaprifoliaceaeLinnaeaLinnaea borealis

Ecology

A creeping perennial, woody at the base, of both native and planted Pinus sylvestris woodland, where it occurs in slight to moderate shade, on barish ground or leaf litter, sometimes with an acidic heathy herb flora. It spreads vegetatively and by seed, though seedling establishment seems largely restricted to disturbed ground. 0-730 m (Easterness).

Status

Native

World Distribution

Circumpolar Boreal-montane element.

© Pete Stroh

Broad Habitats

Coniferous woodland

Light (Ellenberg): 5

Moisture (Ellenberg): 5

Reaction (Ellenberg): 2

Nitrogen (Ellenberg): 2

0

Salt Tolerance (Ellenberg): 0

January Mean Temperature (Celsius): 1.6

July Mean Temperature (Celsius): 12.7

Annual Precipitation (mm): 1008

Life form information

Height (cm): 10

Perennation - primary

Perennial

Life Form - primary

Chamaephyte

Woodiness

Semi-woody

Clonality - primary

Extensively creeping and rooting at nodes

Count of 10km squares in Great Britain: 93

Count of 10km squares in Ireland: 0

Count of 10km squares in the Channel Isles: 0

Atlas Change Index: 0.07

Distribution information

JNCC Designations

NBNSYS0000004330

Scarce Atlas Account

Scarce Atlas Account: 

Linnaea borealis L.

Twinflower

Status: scarce

 

 

L. borealis usually occurs in native pinewoods and old plantations. It grows as a spreading mat with horizontal creeping woody stems that produce adventitious roots. Typical associates in pinewoods are Calluna vulgaris, Deschampsia flexuosa and Vaccinium myrtillus. Goodyera repens is also a common associate and at some localities Moneses uniflora grows in proximity. The plant occasionally occurs outside woodland in more upland habitats, growing in the shade of mountain rocks. It has been recorded at c. 800 metres in the Grampians and c. 600 metres on Ben Chonzie (Wilson 1956).

L. borealis is a creeping woody perennial and regenerates by producing rejuvenating shoots from buds on the main axis and other parts of the plant (Hagerup 1921). The plant is therefore able to spread in any direction and in favourable conditions may rapidly cover several square metres. It requires slight shade to flower well and in conditions too dark for flowering it may persist in a vegetative state. L. borealis is adapted for cross pollination although it is self-fertile. The funnel-shaped flowers are mainly suited to insects with short mouthparts. Flies, solitary bees, syrphids and some Lepidoptera are the main insect visitors (Barrett & Helenurm 1987; Knuth 1908). Fruits are adapted for animal dispersal by possessing two partially enclosed bracts with viscid hairs. The fruit breaks off below the bracts and sticks to fur and feathers (Ridley 1930). The fruits have been recorded on mountain hares, willow grouse and red grouse in Sweden (Ericson 1977; Ridley 1930). Seedling establishment seems to be rare and has been reported to any great extent only in disturbed ground (Ericson 1977).

L. borealis seems to be decreasing and there is little doubt that sites have been lost through clearance of native woodland. Many extant populations occur in old plantations where the timber is reaching or has reached economic maturity. Modern techniques of harvesting and ground preparation for replanting may exterminate these populations. 

L. borealis has a circumpolar distribution. The three subspecies which are recognised differ slightly in leaf and flower shape. Subsp. borealis occurs from western Europe through northern Eurasia to Alaska, where it meets subsp. americana which occurs in most of North America and in Greenland. Subsp. longiflora is restricted to Pacific N. America (Hulten 1970; Hulten & Fries 1986).

 

 

P. S. Lusby

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

Atlas (265b)
Hultén E, Fries M
1986.  Atlas of north European vascular plants north of the Tropic of Cancer. 3 vols.
Meusel H, Jäger EJ
1992.  Vergleichende Chorologie der zentraleuropäischen Flora. Volume 3. 2 vols.
Stewart A, Pearman DA, Preston CD
1994.  Scarce plants in Britain.
Swan GA
1993.  Flora of Northumberland.