Juniperus communis
Common names: Juniper, common juniper
Irish name: Aiteal
Latin name: Juniperus communis
Family: Cupressaceae
Origin: Native
Tree type: Evergreen conifer
How it looks
Shape, bark, twigs
The tree can grow to 10m in height. The bark is red to grey-brown, peeling off in thin strips with age. Twigs are a red-brown colour.
Leaves
The needle-like leaves, which are present all year around, are blue-green with a single pale band on its upper surface. Each needle is between 10 and 15mm long and tapers to a sharp, prickly point. Needles are found in threes, alternating around the twigs.
Flowers
Juniper has separate male and female trees known as dioecious. Male trees produce small, yellow, cone-like flowers found in leaf axils near the tips of twigs. Female trees have green flowers which look berry-like. Male flowers release pollen from May to June that pollinates female flowers via the wind.
Fruits
Once pollinated by the wind, the flowers on a female tree develop into aromatic, berry-like seed cones, which start green and slowly turn purple, taking around 18 months to ripen fully. Each seed cone, around 6 mm in diameter, holds three to six black, triangular seeds. Because of their long ripening period, berries occur at different stages of development throughout the year. Birds eat the seeds and help to disperse them.
Juniper seeds have a slow germination rate and require two winters of dormancy before they sprout and grow. This tree can also reproduce vegetatively. This means that branches that may have fallen can develop roots and grow into a new tree.
Similar species
Common juniper is not easily confused with other species. However, there are many cultivars sold in garden centres.
Where to find it
The common Juniper is native to Ireland and many other places, having the most widespread native range of any conifer in the world. It thrives in open habitats on rocky limestone, moorland, and woodland edges. It can grow on both acid and alkaline soils provided they are well-drained to moist and at altitudes of way over 1000m above sea level. It is often found as a low-growing, spreading shrub or small tree.
Cultural importance
History
Juniper is referred to by a number of different names in Irish Medieval texts, including: ibhur craigi, meaning 'rock yew', iubhar beinne or 'mountain yew', beaman Brighde which means 'the gapped one of Brigit', and biora leacra which translates as 'spines of the rock'. In early Ireland (400-1100 AD), Juniper was considered along with Blackthorn, Elder, Spindle, Whitebeam, the Strawberry tree and aspen as one of the ‘Lower Divisions of the Wood’. It appears to have been valued mostly for its medicinal properties and features in later Medieval medicine lists as result.
Juniper berries are renowned for their use in flavouring gin and whiskey, especially in Scotland, and during the nineteenth century juniper berries were exported from Scotland to Dutch gin distilleries for this purpose. The berries were also widely used in cooking
It is possible that the use of berries in alcohol and cooking was a way of administering them for medicinal purposes of which they had many. There is evidence to suggest that they were used in ancient Egypt as early as 1500 BC to cure tapeworms, whilst the Romans used the berries to cure stomach ailments and for purification. They were also used in the Medieval period to support women in labour.
In other countries, such as France, Juniper wood was burnt in order to purify the air in order to prevent infection and was used in this way during times of plague. It has also been suggested that in some ancient cultures it was to burnt in order to purify temples, and that in Celtic traditions the smoke was used to commune with the Otherworld during the festival of Samhain, what is now modern-day Halloween.
Myth, Legend and Folklore
Linked to its purifying properties, Juniper was deemed to have protective powers. It was believed that if placed inside the house it would guard against misfortunes such as fire, and if placed above one’s door it would ward off witches. Likewise, in some European countries, Juniper smoke was thought to protect against witches.
In Syria, juniper was associated with the fertility goddess Ashera or Astarte, while the Old Testament, refers to the protective powers of the tree where a juniper is said to have given shelter the prophet Elijah when he was fleeing from Queen Jezebel. A similar theme arises the Bible story where the infant Jesus and his parents, fleeing from King Herod’s soldiers, are safely hidden from them by a juniper tree.
Value to wildlife
Common juniper provides dense cover for nesting birds, such as the song thrush, goldcrest and firecrest. Several types of birds enjoy eating the fruits, including thrush species such as the ring ouzel and fieldfare. It is the food plant for caterpillars of many species of moths, including the juniper pug, juniper carpet, and chestnut-coloured carpet moths. Although the leaves are prickly, new shoots feed deer and rabbits.
Threats
Although not an endangered species worldwide, Ireland's common juniper range and abundance are shrinking. This is thought to be because of overgrazing by deer, rabbits, and domestic livestock.
Juniper is susceptible to the fungus-like pathogen called Phytophthora austrocedrae, which infects the plant via the roots, causing foliage dieback and tree death. Though it has not been recorded in Ireland, it has been found in the northern parts of the UK, which increases the likelihood of making it over to Ireland.
To learn more about threats to Irish trees, visit 'Threats to Trees.'
Uses
Juniper berry-like cones are most famous for flavouring gin, but recently, they have also become a popular spice used in liqueurs and sauces, particularly in European cuisine. Its aromatic wood can be used for smoking food. In terms of its medicinal properties, the berry-like cones produce an oil that can aid respiratory and digestive problems and is also used in aromatherapy and perfume. Juniper timber is a popular wood for turnery and carving due to its warm, golden colour and aromatic scent.
References
Kelly, F. 1999. Trees in Early Ireland, Augustine Henry Memorial Lecture 11th March 1999, Irish forestry: Journal of the Society of Irish Foresters, 56, pp. 39-57.
MacCoitir, N. 2015. Ireland’s Trees: Myths, Legends and Folklore. Cork: The Collins Press.
Stroh, P. A., Humphrey, T. A., Burkmar, R. J., Pescott, O. L., Roy, D. B., & Walker, K. J. 2023. BSBI Online Plant Atlas 2020. https://plantatlas2020.org/atlas
Tree Council of Ireland. 2024. Native Irish Trees. Tree Council of Ireland. https://www.treecouncil.ie/native-irish-trees
Trees for Life. 2023. Juniper mythology and folklore, Trees for Life Website. https://treesforlife.org.uk/into-the-forest/trees-plants-animals/trees/juniper/juniper-mythology-and-folklore/
Woodland Trust. 2024. A-Z of British trees. Woodland Trust. https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/