Blackthorn or Plum: how to tell them apart?
Blackthorn and Plum look alike and are often mixed up. Here is how to tell them apart, feature by feature, with their photos and the details to look for.
⚡ The quick answer
Blackthorn
Prunus spinosa
Plum
Prunus domestica
The blackthorn has much smaller, astringent fruits, and thorny twigs; the cultivated plum has none.
🍃 Leaves
Small, ovate, finely toothed
Elliptic to obovate, toothed, slightly downy beneath
🌸 Flowers
White, densely covering the twigs before the leaves
White, solitary or in groups of 2-3, appearing early in spring
🍎 Fruits
Small blue-black plums (sloes), very sour, covered in bloom
Fleshy drupe (plum), purple, yellow or red depending on variety, with a flattened stone
🪵 Bark
Blackish, twigs thorny and rigid
Greyish to dark brown, cracking into scales
📏 Size
1 to 4 m tall, dense thorny bush
3 to 8 m tall
🗺️ Habitat
Hedgerows, waste ground, woodland edges
Orchards and gardens, sometimes naturalised at woodland edges
⚠️ Toxicity
Seeds (stones) and wilted leaves rich in cyanogenic compounds, toxic in large quantities as in other Prunus; the fruits (sloes) are edible after bletting or frost.
Fruit flesh edible; the stone, leaves and bark contain amygdalin (a cyanide precursor), toxic in large quantities
🔎 And from the Plum side
The blackthorn has much smaller, astringent fruits, and thorny twigs; the cultivated plum has none.
🌿 Go further
Want to practise spotting these details on real photos? Floraneo offers profiles and quizzes for dozens of look-alike species.
ℹ️ Educational profile — do not use it to judge whether a plant is edible or safe.