The bark is black(ish) and it has thorns - so we have Blackthorn. It is sometimes planted in gardens as a deterrent due to it's thorns, but more often it is planted for it's pretty flowers and fruit. It's not very common in Exeter from what I've seen. More often it's found as a shrub or two hidden amongst other plants such as Common Hazel. There is a single Blackthorn shrub next to Homebase in Exeter amongst the other shrubs. I've also found some at the RSPB Bowling Green Marsh nature reserve and a green space near Haccombe Close play area. It is certainly easier to find in the late summer when the fruit is is showing.
Blackthorn is part of the Prunus genus and is native to Europe, western Asia, and locally in northwest Africa. Below are some useful links:
A single Blackthorn shrub hidden amongst some Willows and Elder near Homebase in Exeter, UK.
Close up of Blackthorn leaves
It is spiny and densely branched. Mature trees can grow to a height of around 6-7m, and live for up to 100 years so is quite short lived. The dark brown bark is smooth, and twigs form straight side shoots, which develop into thorns.
Ouch! Watch out for the thorns. As you can see they are quite long
Close up of the thorns
The leaves are slightly wrinkled, oval, toothed and pointed at the tip and tapered at the base. The thorns can be over 3cm and very easily snag and tear through clothes. The thorns are not poisonous thankfully.
The fruit ares small and round and typically dark blue
The fruit is usually in clusters of three or more. Each fruit is usually around 1.5cm across
Blackthorn is a hermaphrodite, meaning both male and female reproductive parts are found in one flower. White flowers appear on short stalks before the leaves in March and April, either singularly or in pairs. Once pollinated by insects, the flowers develop into the blue-black fruits measuring 1.5cm across. The fruit is often eaten by birds and the fruit is used to make slow gin.
  • Blackthorn, also known as 'sloe', is a small deciduous tree native to the UK and most of Europe
  • It is spiny and densely branched, mature trees can grow to a height of around 6-7m, and live for up to 100 years
  • The dark brown bark is smooth, and twigs form straight side shoots, which develop into thorns
  • The twigs are black and spiny with leaf buds along the spines
  • The leaves are slightly wrinkled, oval, toothed, pointed at the tip and tapered at the base
  • Blackthorn is a hermaphrodite, meaning both male and female reproductive parts are found in one flower
  • White flowers appear on short stalks before the leaves in March and April, either singularly or in pairs.
  • Once pollinated by insects, the flowers develop into blue-black fruits measuring up to 1.5cm across
  • Blackthorn is native to Europe and western Asia. It can also be found in New Zealand and eastern North America
  • It grows best in moist, well drained soil and thrives in full sunlight
  • It grows naturally in scrub, copses and woodlands, but is commonly used as a hedging plant
  • Early flowering, blackthorn provides a valuable source of nectar and pollen for bees in spring.
  • Its foliage is a food plant for the caterpillars of many moths, including the lackey, magpie, common emerald, small eggar, swallow-tailed and yellow-tailed
  • It is also used by the black and brown hairstreak butterflies
  • Birds nest among the dense, thorny thickets
  • The birds also eat caterpillars and other insects from the leaves, and feast on the berries in autumn
  • The expression "sloe-eyed" for a person with dark eyes comes from the fruit, and is first attested in A. J. Wilson's 1867 novel Vashti
  • Blackthorn was long associated with witchcraft, and it is said that witches' wands and staffs were made using blackthorn wood
  • The shrub, with its savage thorns, is traditionally used in Britain and other parts of Northern Europe to make a cattle-proof hedge
  • The timber is hard wearing and tough, light yellow with a brown heartwood
  • It was traditionally used for making walking sticks and tool parts
  • It burns well, and is often used as firewood
  • Blackthorn is used as a hedging shrub, particularly in wildlife gardens
  • The sloes are used for wine making and preserves, and, most commonly, flavouring gin
  • In the British Army, blackthorn sticks are carried by commissioned officers of the Royal Irish Regiment
  • The tradition also occurs in Irish regiments in some Commonwealth countries
  • Some people apply blackthorn flower directly to the skin for rashes, “skin impurities,” and “blood purification.
  • In foods, blackthorn flower is used in herbal teas as a colouring agent
  • A marmalade made from the berry is used for upset stomach
  • Blackthorn berry is used as a mouth rinse (gargle) for mild sore throat and mouth
  • Wine made from fermented sloes is made in Britain, and in Germany and other central European countries
  • Sloes can also be made into jam and, used in fruit pies, and if preserved in vinegar are similar in taste to Japanese umeboshi. 
  • The juice of the fruits dyes linen a reddish colour that washes out to a durable pale blue.
Scientific classification
Kingdom:Plantae
(unranked):Angiosperms
(unranked):Eudicots
(unranked):Rosids
Order:Rosales
Family:Rosaceae
Genus:Prunus
Subgenus:Prunus
Section:Prunus
Species:P. spinosa
Binomial name
Prunus spinosa
If there is anything out of place or wrong please contact me. Equally if there is anything you wish to add please let me know. The more information we have about Blackthorn the better. Many thanks!