The following blog post was written by Courtney Kemnitz, a Digitiser in the RBGE Herbarium. Courtney is digitising the British Isles collection. This series of blog posts will spotlight a particular species that has been digitised within this collection.

A close up of flowers, Prunus spinosa L. by: Gavin Harris during Apr. 2015 - Image shows close up of 5-petaled white flowers on a branch, with blurred out background.
A close up of flowers, Prunus spinosa L. by: Gavin Harris during Apr. 2015 –   

Prunus spinosa, commonly known as the blackthorn, is a native shrub or small tree found throughout the United Kingdom and Ireland. It is known for its sharp thorns, white flowers in the spring, and bitter sloe berries in the autumn. 

Prunus spinosa has a long and rich history in the folklore of the British Isles and the Isle of Ireland. It is associated with a variety of deities and mythical creatures, including the Cailleach, a Celtic winter goddess, another  Celtic goddess named Brigid, the fairy folk (e.g. Ireland’s Lunantisidhe), and the Welsh witch Cerridwen. 

The association between Prunus spinosa and witches/witchcraft likely stems from a combination of factors, including the use of blackthorn wood in witch wands and staffs, the association of blackthorn trees with death and cemeteries, and the eerie ambience often associated with blackthorn trees. 

Here are a few specific examples of blackthorn folklore from the UK and Ireland: 

  • It is said that the fairies live in blackthorn groves and that their queen rides a blackthorn steed. In some traditions, the blackthorn tree is also seen as a gateway to the fairy realm. 
  • Blackthorn wands and staffs were often used in Celtic magic and rituals. 
  •  In Christian folklore, witches used the wood to make their wands and staffs, such as Edinburgh’s ‘Wizard of West Bow,’ Major Thomas Wier. He was said to have a blackthorn staff carved with a Satyr’s head, given to him by the devil that he used for witchcraft.   
  • Its thorns were used in protective spells and rituals.  
  • The trees are haunted by ghosts of witches 
  • Due to the tree’s connection with fairies, it was considered bad luck to cut the tree on Beltane or Samhain 
  • In Celtic mythology, the P. spinosa was seen as a sacred tree of protection. It was believed that the tree’s thorns could ward off evil spirits and harm. 

The blackthorn tree is truly enchanting, and its folklore is diverse and captivating. It has been both revered and feared for centuries, and its mystique continues to captivate people today. 

A Closer Look 

Prunus spinosa by Carl Axel Magnus Lindman, in Bilder ur Nordens Flora (between 1917 and 1926). Illustration of Prunus spinosa branch and cross section of fruit and flowers.
Prunus spinosa by Carl Axel Magnus Lindman, in Bilder ur Nordens Flora (between 1917 and 1926) 

Name: Prunus spinosa L.  

Family: Rosaceae 

It was first described scientifically in 1753 by Swedish Carl Linnaeus in Species Plantarum   

Common Names* in the British Isles and the Isle of Ireland 

  • English: Blackthorn (BLAK-thorn), sloe (sloh) 
  • Scots: slae (SLAY) 
  • Scots Gaelic: droighneag (DROO-nyak), sluach (SLOO-akh), àirne (AHR-nyeh) 
  • Irish Gaelic: Draighean (drain OR dray-un) 
  • Welsh: draenen ddu (DRAI-nen THEE) 
  • Manx: Drine arn (DRYN ARN) 
  • Cornish: spernen dhu (sper-nen do) 
  • Old English: slāh (SLAH) 

Species Description

A spiny and densely branched shrub or small tree with small, narrow deciduous leaves. It typically reaches a height of about 6-7 metres (about 19-23 feet) and can live up to 100 years. The tree is characterised by its dark brown bark and thorns that protrude at right angles, which give it the common name “blackthorn.” 

A specimen  of Prunus spinosa L. in flower in the living collection at Dawyck Botanic Garden  by: Gavin Harris during Apr. 2014 - Image depicts a Prunus spinosa tree in flower in the foreground on the right-hand side of a path, trees and shrubs can be seen behind the tree on either side of the path.
A specimen of Prunus spinosa L. in flower in the living collection at Dawyck Botanic Garden by: Gavin Harris during Apr. 2014 –     

In spring, the blackthorn produces small bowl-shaped white flowers with five petals. These flowers appear just before the leaves and have a musky fragrance. 

The tree also bears bluish-black fruit known as “sloes.” These fruits, have a white bloom or powdery coating on their surface. Like cherries and apricots, sloes are stone fruits. However, the flesh of sloes is bitter and inedible for humans.

Closeup of the fruit (known as sloe). Image taken in Sweden by Martin Olsson (CC BY-SA 3.0) Fruit are in clusters, each is round and dark blue with a paler powdery blue coating. Smaller branchlets surround the fruit bearing leaves.
Closeup of the fruit (known as sloe). Image taken in Sweden by Martin Olsson (CC BY-SA 3.0) 

It thrives in a variety of habitats. It is commonly found in woodlands, hedgerows, scrublands, and open fields. Blackthorn is adaptable and can tolerate a range of soil conditions. 

Royal Botanic Garden Edinburgh (RBGE) Herbarium Specimens 

Total number of Specimens held in the British Collection within the Herbarium: 51 Specimens 1

The digitisation of this species within our collections from the British Isles is now complete. This allows us to see how our collections are distributed and compare this to the species range data recorded by the Botanical Society of Britain and Ireland.

Break down by Geographical Region

Country Specimen Count 
Scotland 36 
England 15 
Channel Islands 
Ireland  (Republic of Ireland & Northern Ireland) 


Prunus spinosa is found throughout the British Isles and Ireland, typically inhabiting the fringes of woodlands or old hedgerows. While native to Europe and western Asia, it has been extensively planted, making it challenging to distinguish its native and non-native range in certain regions. This is particularly true in Scotland, where it seems to have been introduced in some areas like the Isle of Skye. 

Prunus spinosa BSBI Online Plant Atlas 2020 Distribution Overview Map of the British Isles and Ireland.
Distribution of Prunus spinosa L. in the British Isles and Ireland (BSBI Plant Atlas 2020) 

For a map of the worldwide distribution of Prunus spinosa L. visit Plants of the World Online. 

Uses, Past & Present in the British Isles and the Isle of Ireland   

  • The fruit, known as sloe, is used for flavouring alcoholic beverages (e.g. sloe gin) 
  • Timber (e.g. in Ireland it is the traditional wood for making shillelaghs, a type of walking sitck) 
  • Hedgerow 
  • Sewing needles 
  • Metal-work 
  • Medicine 

Sayings from the British Isles and the Isle of Ireland 

Here are a few sayings from the British Isles and Ireland related to blackthorn and its folklore: 

“Blackthorn Winter”

In rural England, it refers to a spell of cold weather that occurs in early spring or summer when blackthorn flowers are in bloom. 

“Many sloes, many groans” or “Many sloes, many cold toes”

These sayings suggest that if there is a plentiful harvest of sloe berries (the fruit of the blackthorn), it indicates a hard winter ahead, which may lead to poverty and hardship. 

These sayings reflect the connection between natural phenomena, such as the flowering and fruiting of blackthorn and other trees, and the anticipation of weather conditions, particularly during the winter season.   

Literary References from the British Isles and the Isle of Ireland 

Prunus spinosa L. by: Gavin Harris during Jun. 2013 - 
Tree in leaf in foreground on right hand side of a path in a wooded area.
Prunus spinosa L. by: Gavin Harris during Jun. 2013 – 

The inclusion of Prunus spinosa, or blackthorn, in literature and folklore signifies its cultural importance and the profound interplay between nature and storytelling in the UK and Ireland. Here are a few instances of literary references to blackthorn in these regions: 

“Tá mo ghrá-sa mar bhláth na n-airne ar an draighneán donn” 

Seán Tóibín,  Troscan na mBanta (1967) 

[English Translation]

‘My love is like the flower on the dark blackthorn’. i.e. fair of skin with dark hair.

Seán Tóibín,  Troscan na mBanta (1967) 

[English translation]   

“First came the Alder, 
Which struck the first blow. 
Willow and Rowan 
Came late to the muster. 
The spiny Blackthorn 
Was hungry for bloodshed.” 

Câd Goddeu, Llyfr Taliesin (The Battle of the Trees, Book of Taliesin) (14th century poem) 

“The twa appear’d like sisters twin, 
In feature, form, an’ claes; 
Their visage wither’d, lang an’ thin, 
An’ sour as onie slaes” 

 Robert Burns, The holy fair (1875)

[English translation] 

“The two appeared like twin sisters, 
In feature, form, and clothes; 
Their visage withered, long and thin, 
And sour as any sloes” 

Robert Burns, The Holy Fair (1785)

“But the Entwives gave their minds to the lesser trees…and they saw the sloe in the thicket, and the wild apple and the cherry blossoming in the spring, and the green herbs in the waterlands in summer, and the seeding grasses in the autumn fields.”

JRR Tolkien, Lord of the Rings Two Towers Book 3, Chapter 4 (1954) 

Prunus spinosa is a fascinating tree with a rich history of folklore and mythology in the British Isles and the Isle of Ireland. It is a reminder of the deep connection between humans and the natural world. 


  1. Please note, that the Herbarium contains more specimens of Prunus spinosa from other parts of the world. These figures are not included. ↩︎