Blackthorn
Prunus spinosa
A dense, suckering shrub of hedge and scrub, almost black-barked, its stiff side-shoots ending in long sharp thorns. It flowers on bare wood in early spring, small white five-petalled blossom smothering the twigs before any leaf shows. The autumn fruit, the sloe, is a small blue-black plum with a grey waxy bloom, far too sour and drying to eat raw but the basis of sloe gin, jellies and sauces.
Hedgerows, wood edges, scrub and coastal thickets on most soils, common throughout Britain and Ireland. Spreads by root suckers into dense impenetrable stands and is widely planted as stockproof hedging.
The thorns puncture deeply and the wounds readily turn septic, so wear gloves and clean any scratch properly. Raw sloes are intensely astringent rather than poisonous, but the stones contain cyanogenic compounds: avoid crushing them into preserves or leaving broken stones in long-steeped gin.
Always use more than one reference to confirm a plant. You are responsible for what you choose to forage.
Flowering on bare wood
Dense white five-petalled flowers open in early spring on leafless black twigs, so the whole shrub reads as a white line in a still-bare hedge. Hawthorn, the other white hedgerow blossom, flowers later and only once it is in full leaf.
Thorns and bark
The bark is very dark, almost black, and the short side-shoots taper to hard spine points that often still bear buds or leaves. This is a true thorn on a shoot, not a prickle peeling off the bark as on a rose or bramble.
Fruit
Spherical, 10–15 mm, blue-black beneath a pale grey bloom that rubs off to a shine under a thumb, carried singly or in twos. Cut one and it is a miniature plum: green-yellow flesh around a single flattened stone, never several seeds.
Leaves and habit
Small dull oval leaves 2–4 cm long with fine teeth, appearing after the flowers, on a low, densely twiggy shrub that suckers outwards into thickets. Cherry plum, which flowers at much the same time, is a taller single-stemmed tree with glossier leaves and little or no thorn.
Updated 2026-08-07T21:05:40.674Z · Part of the shared Foragers Log catalogue · Fruit