Calluna vulgaris is the sole species in the genus Calluna in the family Ericaceae.
It is a low-growing perennial shrub growing to 20 to 50 centimetres tall, or rarely to
1 metre and taller, and is found widely in Europe and Asia Minor on acidic soils in open
sunny situations and in moderate shade.
It is the dominant plant in most heathland and moorland in Europe, and in some bog vegetation
and acidic pine and oak woodland.
It is tolerant of grazing and regenerates following occasional burning, and is often
managed in nature reserves and grouse moors by sheep or cattle grazing, and also by light
burning.
Referred to as Erica in all the old references, Calluna was separated from the closely related
genus Erica by Richard Anthony Salisbury, who devised the generic name Calluna from
the Greek kallunein, "beautify, sweep clean", in reference to its traditional use in besoms.
The specific epithet vulgaris is Latin for 'common'.
Calluna is differentiated from Erica by its corolla and calyx each being in four parts
instead of five.
Calluna has small scale-leaves borne in opposite and decussate pairs, whereas those of Erica
are generally larger and in whorls of 3-4, sometimes 5.
The flowers emerge in late summer; in wild plants these are normally mauve, but white-flowered
plants also occur occasionally.
Unlike Erica, Calluna sometimes sports double flowers.
Calluna is sometimes referred to as Summer heather to distinguish it from winter or spring
flowering species of Erica.
Cultivation
Despised until the 19th century for its associations with the most rugged rural poverty, heather's
growth in popularity may be paralleled with the vogue for alpine plants.
It is a very popular ornamental plant in gardens and for landscaping, in lime-free areas where
it will thrive, but has defeated many a gardener on less acid soil.
There are many named cultivars, selected for variation in flower colour and for different
foliage colour and growing habits.
Different cultivars have flower colours ranging from white, through pink and a wide range
of purples, and including reds.
The flowering season with different cultivars extends from late July to November in the
northern hemisphere.
The flowers may turn brown but still remain on the plants over winter, and this can lead
to interesting decorative effects.
Cultivars with ornamental foliage are usually selected for reddish and golden leaf colour.
A few forms can be silvery grey.
Many of the ornamental foliage forms change colour with the onset of winter weather, usually
increasing in intensity of colour.
Some forms are grown for distinctive young spring foliage.
Cultivars include ‘Beoley Crimson’, ‘Boskoop’, ‘Cuprea’, 'Firefly',‘Long White’.
The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:
Uses Heather is an important food source for various
sheep and deer which can graze the tips of the plants when snow covers low-growing vegetation.
Willow Grouse and Red Grouse feed on the young shoots and seeds of this plant.
Both adult and larva of the Heather Beetle Lochmaea suturalis feed on it, and can cause
extensive mortality in some instances.
The larvae of a number of Lepidoptera species also feed on the plant, notably the small
emperor moth Saturnia pavonia.
Formerly heather was used to dye wool yellow and to tan leather.
With malt, heather is an ingredient in gruit, a mixture of flavourings used in the brewing
of heather-beer during the Middle Ages before the use of hops.
Thomas Pennant wrote in A Tour in Scotland that on the Scottish island of Islay "ale
is frequently made of the young tops of heath, mixing two thirds of that plant with one of
malt, sometimes adding hops".
The use of heather in the brewing of modern heather beer is carefully regulated.
By law, the heather must be cleaned carefully before brewing, as the undersides of the leaves
may contain a dusting of an ergot-like fungus, which is a hallucinogenic intoxicant.
From time immemorial heather has been used for making besoms, a practice recorded in
Buy Broom Buzzems a song probably written by William Purvis from Newcastle-upon-Tyne,
England.
Heather honey is a highly valued product in moorland and heathland areas, with many beehives
being moved there in late summer.
Not always as valued as it is today, it was dismissed as mel improbum by Dioscurides.
Heather honey has a characteristic strong taste, and an unusual texture, for it is thixotropic,
being a jelly until stirred, when it becomes a syrup like other honey, but then sets again
to a jelly.
This makes the extraction of the honey from the comb difficult, and it is therefore often
sold as comb honey.
White heather is regarded in Scotland as being lucky, a tradition brought from Balmoral to
England by Queen Victoria and sprigs of it are often sold as a charm and worked into
bridal bouquets.
Calluna vulgaris herb has been used in the traditional Austrian medicine internally as
tea for treatment of disorders of the kidneys and urinary tract.
Invasive species The plant was introduced to New Zealand and
has become an invasive weed in some areas, notably the Tongariro National Park on the
North Island and the Wilderness Reserve on the South Island, overgrowing native plants.
Heather beetles have been released to stop the heather, with preliminary trials successful
to date.
Chemistry The shoots of Calluna vulgaris contain the
phenolic compounds chlorogenic acid, its 3-O-glucoside, 3-O-galactoside and 3-O-arabinoside.
Cultural references Heather is seen as iconic of Scotland, where
the plant grows widely.
When poems like Bonnie Auld Scotland speak of "fragrant hills of purple heather', when
the hero of Kidnapped flees through the heather, when heather and Scotland are linked in the
same sentence, the heather talked about is Calluna vulgaris.
The Robert E. Howard story "Kings of the Night" frequently references heather when describing
a portion of what would become Great Britain.
The English folksong, Scarborough Fair, has the line, "Gather it all in a bunch of heather."
A poem written by Robert Louis Stevenson, Heather Ale: A Galloway Legend, tells a story
of a long-forgotten drink of heather ale.
Purple heather is one of the two national flowers of Norway
See also List of Lepidoptera that feed on Calluna
Heath.
Erica References