Common names: Strawberry Tree, Killarney Strawberry tree 

Irish name: Caithne 

Latin name: Arbutus unedo 

Family: Ericaceae 

Origin: debated if it is native or not 

Tree type: Evergreen broadleaf tree

How it looks

Shape, bark, twigs 

The Strawberry tree can grow to 15m in height. It has a distinguishing reddish-brown tactile bark that peels off to reveal a smooth, cinnamon-coloured layer underneath.  

Leaves

Tough, glossy, dark green, rounded leaves with serrated edges are on the tree all year round (evergreen). The leaf stalks (petioles) are pink.

Flowers 

From October to April, the strawberry tree is in bloom with small, bell-like flowers. They flower in bunches that dangle down on a short, leafless stem. Each flower is typically 8mm long and 5mm across, sometimes white, but can also be tinged with red, pink, or green. The flowers of the Strawberry tree have both male and female organs known as hermaphrodite.

Fruits 

This tree got its common name because of the strawberry-like fruit it produces. After pollination by insects, the flowers develop into fruits, starting green and turning orange and red when ripe. Ripening can take up to 12 months, meaning both mature fruit and flowers are commonly on the tree at the same time. The fruit will drop off only when ripe, usually in late autumn and early winter. The fruits contain seeds, which can be spread by the animals that eat them. 

Similar species 

In Ireland, a hybrid of Arbutus unedo and A. andrachne was commonly planted in gardens in the 19th century. The hybrid is a bigger tree with more heavily peeling red bark and smaller fruit than Arbutus unedo.

Where to find it

The strawberry tree is native to the Mediterranean Basin and Western Europe and has long been considered native to the West of Ireland. However, a study published in the British & Irish Botany journal in 2021 by Sheehy-Skeffington and Scott of the University of Galway challenges this belief. The genetics of Kerry's strawberry trees were similar to those found in northern Spain. The distribution of Strawberry trees in Kerry and Cork matches those of Bronze Age copper mines, where Spanish miners visited Ireland to extract copper. The study suggests that Spanish miners imported Strawberry trees around 4,000 years ago to make wine and produce charcoal. 

Today, strawberry trees in Ireland are found in Co. Kerry’s Killarney district, on the lake's shores and islands, and in woodland margins on exposed crags or cliffs. It is also found sporadically in West Cork and around Co. Sligo’s Lough Gill. 

Tolerant of acid and alkaline soils and exposed coastal positions, this evergreen tree is resilient but prefers a sheltered spot in full sun and well-drained soils. It is not able to tolerate waterlogged soil.

Cultural importance

History | Myth | Literature

History 

As mentioned above, it is possible that people in Ireland have been interacting with the strawberry Tree since the early Bronze Age (c. 2500-1800 BC) on account of its value for the production of alcohol and charcoal. Research has indicated that if this theory is correct, the ancestor trees of the Irish strawberry tree may have been associated with copper mining in the Cantabria region of northern Spain and originally sourced from the San Sebastien area. 

In the early Irish law texts the strawberry tree is included as one of the ‘Lower divisions of the wood’ perhaps due to its suitability for making charcoal. Although the strawberry tree was considered less valuable than an oak, one could still incur a compensation fine equivalent to a yearling heifer for damaging or destroying one. 

One source suggests that the strawberry tree had declined in Ireland by the sixteenth century as a result of its widespread use in charcoal making for various industries. At the same time, the strawberry tree seems to have enjoyed popularity during the sixteenth century, in that it was exported from Ireland for planting in English estates.  

The popularity of planting strawberry trees on estate lands seems to have continued into the nineteenth century. There is a record from 1800 of a man crossbreeding Arbutus unedo, the species found in Spain and Ireland, with the Arbutus andrachne, the Cyprus Strawberry tree to create an even more ornamental hybrid species known as Arbutus x arachnoids or Arbutus hybrida. The much-loved tree which currently stands outside the RTÉ canteen in Dublin is thought to be one of these hybrids and is more than 100 years old. 

As the strawberry tree grows mainly in the southwest of Ireland or in pockets along its western seaboard, it features in placenames in these regions. Examples include Arbutus Island or Oileán na Caithne, in County Kerry, and Ardcanny or Ard Caithne, County Limerick, which tranlsates as ‘height of the arbutus’. 

Myth, Legend and Folklore 

There is very little folklore about the strawberry tree, perhaps because it is so rare and confined to certain parts of the country. However, the berries of the strawberry tree do appear in the mythological story, The Pursuit of Diarmuid and Grainne. Diarmuid and Grainne bring berries from a strawberry tree in the ‘Promised Land’ or otherworld to Ireland. On their way through what is present day Moy in County Sligo, they drop one of the berries which grows into a magical tree. As the tale goes, anyone who ate the fruit of this tree would never be ill and would have their youthfulness restored. This description of the tree suggests that it was seen almost as an elixir of life and thus endowed with magical properties.

Literature 

The best-known example of the strawberry tree in literature is perhaps the traditional Irish song, My Love is Like an Arbutus, written by Alfred Perceval Graves, in which he compares his love with the beauty and virtues of the tree: ‘But though ruddy the berry, And snowy the flower, That brighten together, The arbutus bower, Perfuming and blooming, Through sunshine and shower...’. 

Value to wildlife

The strawberry tree is excellent for wildlife; pollinators feed on the nectar and pollen from its flowers, and various birds and small mammals eat its ripe fruits. The dense foliage throughout the year can shelter insects and small animals during the winter. 

The nectar of strawberry tree flowers contains properties which are biologically active against a common and debilitating gut parasite of bumble bees called Crithidia bombi.  The nectar could be a naturally occurring way for bees to withstand the burden of disease, which has been reported to be a contributing factor in pollinator declines.

Threats

Strawberry trees aren’t generally prone to serious pests or diseases.

Uses

The strawberry tree fruit is edible, but as the Latin name unedo, meaning ‘eat only once’ – implies, it is not very palatable. However, its berries naturally produce alcohol when mature, even while on the tree, and were commonly used in Mediterranean countries as a source of alcohol. In Portugal, the fruit of the strawberry tree is used to make a traditional liqueur called 'medronho'. In the Mediterranean region, the fruit is used to make jam, marmalades, yoghurt and brandy.  

In Ireland, the strawberry tree is often used in Christmas decorations. It is a popular ornamental plant because of its attractive flowers and fruit and the wood makes great charcoal. It has also been used in folk medicine as an antiseptic, astringent, intoxicant, tonic and as a treatment for rheumatism.

References

Duncan, L. L. 1896. The Quicken-Tree of Dubhros, Folklore, 7(4), pp. 321-330. Online: https://www.jstor.org/stable/1253298 

Irish Independent. 2011. The strawberry tree – a Kerry native with a very bitter bite, Irish Independent, 22 June 2011. Online: The strawberry tree – a Kerry native with a very bitter bite | Independent.ie 

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. 

MacLean, R., 1993. Eat your greens: an examination of the potential diet available in Ireland during the Mesolithic. Ulster Journal of Archaeology, pp.1-8. 

McLoughlin, J. 2016. Trees and woodland names in Irish placenames, Irish Forestry, 73, 239-257. 

McMahon, P. 2023. Island of Woods: How Ireland Lost Its Forests and How to Get Them Back, Dublin: New Island Books. 

O’Donovan, M. and Coille, L., 2005. "My Love’s an Arbutus” by Alfred Perceval Graves, Irish Forestry, 61(1) Available at: https://journal.societyofirishforesters.ie/index.php/forestry/article/view/9971 

Quinn, T. 2020. History of the RTÉ Strawberry Tree, SuperannRTÉ Newsletter, 19 January 2020. Online: History of the RTÉ Strawberry Tree - By colleague Tom Quinn (superannrte.ie) 

Skeffington, M.S. and Scott, N., 2021. Is the strawberry tree, Arbutus unedo (Ericaceae), native to Ireland, or was it brought by the first copper miners?. British & Irish Botany, 3(4), pp. 385-418. 

Skeffington, M.S. and Scott, N., 2022. The strawberry tree in Ireland, Archaeology Ireland, 36(2) (Summer 2022), pp. 24-29. 

Native Irish Trees. Tree Council. Retrieved 11 April 2024, from https://www.treecouncil.ie/native-irish-trees 

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