Hybridises with : Cowberry, the hybrid being called Hybrid Bilbery or (Vaccinium × intermedium). The hybrid has darker leaves and is evergreen, whereas Bilberry itself is deciduous. It is very rare and seems to now only grow in the Cannock Chase area.
Some similarities to :
Blueberry, its larger-berried North American counterpart that was grown commercially in the south of Britain.
Slight resemblance to : Yew 'Berries'. The ripe black bilberries themselves look similar in shape, but not in colour, to the red arils of Yew Trees.
Uniquely identifiable characteristics
Distinguishing Feature :
Northerners call them Bilberries and since they grow mainly in the North of Britain their many alternative names forged further south should be put aside, to be forgotten, for they only cause confusion; Bilberries they should be called.
The upper stems are green and triangular in cross-section, often twisted and knotted. A deciduous low sub-shrub that grows in acid soils, often mixed in with heather on moorland and heathland. The flowers are bell-shaped and reddish with a darker purplish hint, always hanging down facing the ground. Leaves mid-green at first turn yellow, then red in autumn.
Since 2009, Bilberry in the UK has been succumbing to a fungal infection, Bilberry Blight, which turns the affected part of the plant brownish, so as to appear dead. It started in the far south of England, but is spreading, and is now affecting an area of moorland called The Roaches in the millstone grit area of the Pennines. Attempts are being made to stop it spreading.
The berries are blue-black, with a white waxy bloom that wipes off with fingers, and are usually half-hidden beneath the leaves. Delectably edible, and delicious when ripe. Bilberry pies are scrumptious. The fact that it has so many synonyms testifies to the fact that it is widespread and enjoyed by many. Moorland grouse eat the berries, turning their faeces blue, often leaving an intriguing blue splodge on millstone grit rocks. Bilberries have been demonstrated to be good for improving vision, especially night-vision. It has been proposed that Bilberry achieves this by increasing blood flow in the capillaries of the retina.
Bilberry contains at least 15 different anthocyanins, several flavonoids including Quercitrin, IsoQuercitrin, Hyperoside and Astragalin together with Catechol tannins, Ursolic Acid, Caffeic Acid,
Chlorogenic Acid. The anthocyanins are based upon Malvidin, Cyanidin and Delphinidin. The tannins amount to 1.5%.
The anthocyanins are useful in improving eyesight and night-vision and in delaying the onset of cataracts and other eye disorders especially AMD (age-related macular degeneration) which afflicts people over the age of 55 causing blindness starting from the central part of the vision first (unlike tunnel vision where the retina starts degrading around the periphery). The anthocyanins help to regenerate rhodopsin, a purple dye involved in night vision.
The leaves of Bilberry are toxic and have been used to treat diarrhoea and as relief for nausea and indigestion. As well as containing myrtillin and tannins they contain high levels of chromium. Because of their toxicity the medicinal use of the leaves is discouraged.
Anthocyanidins are highly coloured pigments which have anti-oxidant properties. Notice the positive charge on the oxygen atom in all of them. The glycosides of anthocyanidins are called anthocyanins, which are shown in the box below.
Cyanidin is an reddish-yellow pigment and anthocyanidin found not only in Bilberry fruits, but also in blackberries, blueberries, cherries, cranberries, elderberries, hawthorn berries, loganberries, and raspberry. As with most cyanidins, the colour is dependent upon the pH, being red at pH less than 3, violet at neutral acidities (pH 7-8), and blue at pH greater than 11.
Delphinidin imparts a shade of blue to flowers of
Delphiniums where it is in an alkaline environment; in an acid environment it becomes red. One of the glycosides of Delphinidin,
Delphinidin-3-O-glucoside (not shown) is an anthocyanin found in Blackcurrents (examples of anthocyanins found in Bilberry are shown in the box below).
Malvidin is the di-methylated version of Delphinidin, and is a blue pigment found in bilberries and in
Primulas. Malvidin is also found in red wine, where it is in an acid environment and therefore red. In basic conditions it exhibits a blue colour.
It also contains other anthocyanidins, Pelargonidin and
In total, the fruits contain about 0.5% anthocyanidins. High doses of anthocyanidins should be avoided as they can cause haemorrhagic disorders which is especially significant in those taking anti-coagulant drugs such as Warfarin.
Hyperoside is one of the glycosides of the anthocyanin Cyanidin, above. It is the 3-O-galactoside of Quercetin and is found in bilberries,
St John's Wort,
Woundworts and other plants of Genus Stachys.
Myrtillin is an anthocyanin and one of the glycosides of the anthocyanidin Delphinidine, above. It is found in Blackcurrent, the leaves of Blueberry and Bilberry, several plants of the Myrtaceae Family. It is a dark red colour and is responsible for the dark redness of the fruits of the
Sumach Trees. It may have uses in stabilising the blood-sugar level of those suffering from Glycaemia and Diabetes, where it saves the use of insulin which can debilitate some people. Myrtillin could also be described as a methoxylated glucoside of Gallic Acid.