Sorbus aucuparia
Common names: Rowan, Mountain ash
Irish name: Caorthann
Latin name: Sorbus aucuparia
Family: Rosaceae
Origin: Native
Tree type: Deciduous broadleaf tree
How it Looks
Shape, bark, twigs
The rowan can grow up to 15m in height. Its young twigs start hairy and become smooth with age. The bark of the rowan tree is grey-brown and smooth, except for short horizontal lines of 'breathing pores' known as lenticels.
Buds
The buds are arranged alternately along the stem. They are dark grey, with greyish-white hairs all over. The hairs disappear over time and cover the 2-5 bud scales. Buds can measure 6-12 mm long, with terminal buds (found at the tips of branches) larger than lateral buds. Both types of buds are oval and pointed, with the lateral buds growing close to the twig, often curved towards it.
Leaves
The compound leaves of the rowan tree emerge in May and are arranged alternately along the branches. Each leaf consists of 5-8 pairs of opposite leaflets and a single terminal leaflet at the end of the leaf. The leaves can reach lengths of up to 20 cm and widths of 8 to 12 cm. Each leaflet is elongated, oval, and toothed, measuring 2-6 cm long and 1-2.5 cm in width. The leaflets have an asymmetrical base.
Flowers
Rowan trees bloom from May to June, with each individual flower containing both male and female reproductive parts, making them hermaphroditic. Blossom clusters, known as corymbs, consist of approximately 250 individual flowers. Each flower is 8 to 10 mm in diameter and features five creamy-white petals and five small, yellowish-green, triangular sepals.
Fruits
Following successful pollination by insects, the flowers develop into fruits, each cluster (corymb) carrying 80 to 100 of them. Initially green, the fruits typically turn orange or scarlet in August and October. Birds are responsible for dispersing the seeds. The fruit is spherical and measures between 8-10 mm in diameter.
Similar species
Ash (Fraxinus excelsior) or elder (Sambucus nigra); The leaflets of the rowan are serrated and more or less pointed at the end than both of these.
Where to Find it
Rowan trees favour well-drained locations but can adapt and thrive in various soil types. They exhibit remarkable resilience in cold climates and perform well when exposed to both full sunlight and partial shade. These trees can flourish in high-altitude areas, even on rocky terrain, so they are commonly known as "mountain ash." They can be spotted in various natural settings, including open woodlands, rocky cliffs, riversides with rocky terrain, and moorland habitats. However, they tend to avoid dry calcareous soils, heavy clay, and areas with dense shade. Rowan trees are found throughout Ireland and are native to most of Europe, certain parts of Asia, and Northern Africa, with a particular affinity for growing in elevated regions.
Cultural Importance
History | Myth, Legend and Folklore | Literature
Evidence from archaeological excavations indicates that rowan was being used in Ireland for fuel as early as the Bronze Age (c. 2500 – 800 BC), if not earlier, and the construction of bog trackways during the Iron Age (c. 800 BC – 400 AD).
Ancient Irish texts suggest that during the Medieval period, rowan wood was used to make spits for roasting meat and rowan berries were a source of food. However, it doubtless had a number of other uses during this period. As a result, it was designated as one of the ‘Commoners of the Wood’ in the early Irish tree lists. This also meant that if anyone illegally damaged or cut another person's rowan tree they would be fined a penalty fee of up to two milch cows and a three-year-old heifer. The rowan was of such significance that it was used in the early Irish ogham alphabet to represent the ogham character or letter that stands for ‘L’, which takes the following form: 
Traditionally, rowan wood was used for making furniture, tools, musical instruments, spindles and spindle wheels. The berries of the rowan were, and continue to be, used in making jams, syrups, infusions and alcoholic drinks such as rowan berry wine. The bark was used for tanning leather and to make dye for dying cloth. In addition, the bark and leaves were used in traditional herbal medicine to treat a range of complaints. Rowan berries were also used to prepare jams or infusions to address digestive issues and serve as a mouthwash for sore throats. In addition, rowan branches were used as divining rods.
The Irish name for rowan, caorthann or cárthann, features frequently in Irish placenames. For example, it can be found in the placename, Drumkeeran or Droim Caorthainn found in Counties Antrim, Cavan, Fermanagh, and Leitrim, which means ‘ridge of the rowan’. Likewise, it appears in the Galway-based name, Ballykeeran or Béal Átha Chaorthainn, which translates as ‘ford-mouth of the rowan’.
Rowan was traditionally associated with themes of protection, magic, longevity and vitality in myth, legend and folklore both in Ireland and farther afield.
Rowan trees, their red berries in particular, were seen as a protective force in numerous ways. It was believed that if hung in one’s house, rowan would protect against fire and evil. It was placed in barns to protect livestock and milk from supernatural forces, and was also thought to ward off witches. Indeed, people wore rowan on their clothing to protect again magic charms. The rowan was also very prominent during the May Eve celebrations and either burnt, brought into the house or attached to animals in order to protect them from the influence of witches and fairies which was more of a threat on this particular day. It was generally believed that it was the red colour of the berries that provided the protection.
In Wales, Rowans were planted in churchyards to ward off evil spirits, whilst in Scotland it was deemed unlucky to damage a rowan tree. In some Scandinavian countries, the rowan was associated with the God Thor, and it became known as Thor’s Tree. In the same vein, the wood of the rowan was used in nordic countries for inscribing runes for divination.
In an Irish Medieval poem, the rowan is referred to as fid na ndruad which translates as ‘the tree of the druids’. It is thus unsurprising that the tree is frequently linked with magic. In the Irish myths, rowan was often seen as an elixir of life. In the story, ‘The Pursuit of Diarmuid and Gráinne’, Gráinne as Diarmuid to bring her some berries from a magical rowan tree, the Quicken Tree of Dubhros, the fruit of which tasted like honey and brought lasting sustenance, long life and good health. In the story ‘The Siege of Knocklong’, druids ritually burn rowan while uttering magical incantations to deter their enemies.
Writing in the early 1900s, the antiquarian William Gregory Wood-Martin maintained that according to Celtic belief, the first woman on earth came from a rowan tree.
In addition to its presence in Irish Medieval poetry as described above, the rowan has been the subject of many famous writers, featuring in the poetry of William Wordsworth (e.g. The Prelude), Séamus Heaney (e.g. Song) and William Butler Yeats (e.g. The Falling of the Leaves). Indeed, Oliver Southall suggests that Yeats reimagined the rowan as a Celtic emblem.
Value to Wildlife
The flowers of the rowan tree offer pollen and nectar, serving as a vital food source for bees and various other pollinating insects. The leaves are a preferred food for the caterpillars of several moth species, including the larger Welsh wave and autumn green carpet. The rowan's berries, abundant in autumn and winter, provide a valuable food source for birds such as the blackbird, redstart, redwing, song thrush, fieldfare, and waxwing. In winter, the mistle thrush often claims a rowan tree as its feeding territory.
Birds, particularly thrush migrating from Scandinavia to Ireland during the winter, are drawn by the bountiful supply of rowan berries. These birds play a crucial role in dispersing rowan tree seeds, often reaching inaccessible spots like the crowns of oak trees.
Threats
The bacterial disease fireblight was first recorded in Ireland in 1986, and it was likely introduced via infected imported plants. Fireblight is a highly contagious plant disease caused by the bacterium Erwinia amylovora. It affects Crataegus (hawthorn), Malus (apple), Pyrus (pear), Crataegus (hawthorn) and Sorbus (Rowan and whitebeams) trees. In 2023, there were seven outbreaks across 11 counties. Symptoms include:
- Wilting and death of flower clusters following blossom infection.
- Withering and death of young shoots
- Leaves showing necrotic patches, which spread from the leaf margin or the leaf stem, which generally remains attached to the plant.
- Infected fruit turning brown or black; these become shrivelled but remain attached to the plant.
- Cankering, which may spread into the main stem and kill the plant by ring barking it.
If you find signs of fireblight please submit images to DAFM at: plantsandpests@agriculture.gov.ie
Incorrect pruning timing or damage to the tree can make Rowan trees vulnerable to silver leaf disease. This fungal disease enters through wounds during the cool, wet part of the year, blocking the tree's water-carrying vessels and causing wilting, often resulting in tree death.
It is very palatable to browsing animals such as deer.
To learn more about threats to Irish trees, visit ‘Threats to Irish Trees.’
Uses
The wood of the rowan tree displays a pale, yellow-brown hue with a deeper brown heartwood. Although it isn't particularly long-lasting, it possesses strength, hardness, and toughness. This wood is sometimes employed in crafting, furniture making, engraving, and turnery.
The seeds in rowan berries can react with water to generate highly toxic prussic acid. This substance can stimulate the respiratory system in small amounts, but in larger doses, it may lead to respiratory failure and fatality. Therefore, when utilising the fruit for medicinal or culinary purposes, removing the seeds is advisable.
Rowan berries are edible for humans when properly cooked. Although they are sour, they are rich in vitamin C and can create tart jams and meat accompaniments in the form of jelly, tangy syrups, chutneys, juices, wine, and liqueurs. Additionally, they can be dried and combined with cereals to make flour. The leaves and flowers can also be used to make a tea substitute.
In traditional medicine, the fruit is ingested in small amounts as a mash to stimulate appetite or ease an upset stomach, promoting gastric acid production. The flowers and the fruit are used in infusions to manage painful menstruation, constipation, and kidney-related ailments. The bark possesses astringent properties and is utilised in treating diarrhoea
Rowan trees are frequently planted as street trees.
References
- Forestry Focus. Sacred and Magical Trees, Forestry Focus. Sacred and Magical Trees - Forestry Focus
- Newman, C., O’Connell, M., Dillon, M. and Molloy, K. 2007. Interpretation of charcoal and pollen data relating to a late Iron Age ritual site in eastern Ireland: a holistic approach. Vegetation History and Archaeobotany, 16, pp.349-365.
- Raftery, B. 1996. Trackway Excavations in the Mountdillon Bogs, Co. Longford, 1985-1991. Transactions of the Irish Archaeological Wetland Unit 3. Crannóg Publication, University College Dublin.
- Rich, T. C. G., Houston, L., Robertson, A. & Proctor, M. C. F. 2010. Whitebeams, Rowans and Service Trees of Britain and Ireland. A monograph of British and Irish Sorbus L. B.S.B.I. Handbook No. 14. Botanical Society of the British Isles. London.
- Southall, O., 2023. Rowan. London: Reaktion books.
- 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
- Taylor, K. 2006. N18 Ennis Bypass and N85 Western Relief Road Site AR127, Cahircalla More, Co. Clare. Final Archaeological Excavation Report for Clare County Council. Microsoft Word - AR127 final cover.doc
- Tree Council of Ireland. n.d. Native Irish Trees, Tree Council of Ireland. https://www.treecouncil.ie/native-irish-trees
- Trees for Life. N.d. The Rowan in Mythology and Folklore. Trees for Life. Rowan tree mythology and folklore | Trees for Life
- Woodland Trust. n.d. A-Z of British trees, Woodland Trust. https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/