Blackthorn belongs to the family of Rosaceae and to the subfamily of Prunoideae. This dense and spiny shrub grows up to 1-2 m on fringe of forests, clearings and pastures. Its small white flowers appear before the leaves come out, the fruits (called sloe) are 10-12 mm large, blue, cindery stone fruits to be harvested after the first frosts. Small song-birds prefer building their nests inside the spiny branches, while sloe serves as food for small wild animals during winter time. Blackthorn is native to Europe and the Middle East, and it is very widely spread also in Transylvania.

Dried fruits, among them wild fruits and blackthorn have always played an important role in traditional nutrition, especially during Lent. In the 17th century Transylvania, during the rule of Apafi Mihály, dried blackthorn was as valuable that peasant had to pay tenth after the produced quantity.


The flowers must be picked before the leaves come out, around March-April. The sloe is harvested after the first frosts, when it loses its acerbic taste.

Active Substances

The flowers (Pruni spinosae flos) contain flavonoids (kempferol and quercetin glycoside, rutin) and procyanidines. The fruit (Pruni spinosae fructus) contain organic acids, glycose, proteins, iron, vitamin-B1, -B2- and L-ascorbic acid, as well as tannins.


In traditional medicine the dried flowers are the mostly used parts. Its tea has antihypertensive, slightly laxative and diuretic effects. Infuse 1 spoon of dried drug with 2 dl boiling water, macerate it for 20 minutes, and then strain it. Drink 2 dl of tea 3 times daily. In case of kidney and bladder problems mix it with milfoil, tutsan or golden-rod.

The flower infusion has spasmodic effects on stomach, it is an effective fat burning and fat-reducing remedy to be used during slimming diets. The infusion can be made of 2 spoons of dried blackthorn flower boiled in 250 ml of water for 1 minute.  It also can be used for kidney and bladder problems. In order to rest your tired feet pour the infusion into a basin, add one handful of salt and one handful of ash to it and bathe your feet.

Distillated blackthorn flower is used in the cosmetic industry as cover material, invigorator, while the juice of the fruits as invigorator and skin conditioner. Thanks to its high mineral, vitamin and tannin content it tightens, nutrifies and regenerates loose, tired, pale, oily and scaly skin. The sloe can be used for jelly, syrup, wine or spirits.