Blackthorn Prunus spinosa                                                                                                                               

The Blackthorn is a small thorny tree or shrub, usually found in farm hedgerows, but often planted in urban areas. The fruit is called a ‘sloe’ and can be used to make wines and jam. The tree is often confused with the Cherry Plum (also called the Myrobalan Plum), which is described elsewhere in a post. The confusion arises because both have similar looking white flowers in spring. The difference is that the Cherry Plum comes into flower up to 4 weeks earlier than the Blackthorn. The Black and Brown Hairstreak butterflies lay their eggs on Blackthorn thorns in summer. The tiny eggs can be seen throughout the winter as white dots in the fork between the thorn and shoot. The eggs hatch out in spring. The Blackthorn flowers are formed before the leaves from March. The Blackthorn flower is smaller than that of the Cherry Plum and has a shorter stem and so seems to cling to the shoot. The leaves are small and toothed. The thorns are easy to see amongst the leaves.   The fruit was photographed in August and September.


Blackthorn tree August

Blackthorn trees in August

Blackthorn trees spring

The same Blackthorn trees in flower in early May after a cold spring.

Blackthorn leaf

The leaves are small and toothed and tongue-shaped (wider near tip)

Blackthorn leaves and thorn

The thorns are easy to see amongst the leaves.

Blackthorn flowers

Flowers come out before the leaves at the end of March and last through April.

Blackthorn fruits

Fruit in August.

Blackthorn fruits

Fruit at the end of September. This type of fruit is called a drupe by botanists.

Blackthorn bark

Young tree bark.