Prunus spinosa is a largedeciduousshrub or smalltree growing to 5 metres (16 ft) tall, with blackish bark and dense, stiff, spiny branches. Theleaves are oval, 2–4.5 centimetres (3⁄4–1+3⁄4 inches) long and1.2–2 cm (1⁄2–3⁄4 in) broad, with a serrated margin. Theflowers are about1.5 cm (1⁄2 in) in diameter, with five creamy-white petals; they are produced shortly before the leaves in early spring,[3] and arehermaphroditic andinsect-pollinated. Thefruit, called a "sloe", is adrupe10–12 millimetres (3⁄8–1⁄2 in) in diameter, black with a purple-blue waxy bloom, ripening in autumn. In theUnited Kingdom, they are traditionally harvested in October or November, after the first frosts, as this makes the skin softer and easier to process for the purposes of making sloe gin.[4] Sloes are thin-fleshed, with a very stronglyastringent flavour when fresh.[5] Its fruitpersists for an average of 36.7 days, and bears an average of 1 seed per fruit. Fruits average 77.6% water, and theirdry weight includes 10.6%carbohydrates and 0.6%lipids.[6]
Blackthorn usually grows as a bush but can grow to become a tree to a height of 6 m (20 ft). Its branches usually grow forming a tangle.[7][8]
Prunus spinosa is frequently confused with the relatedP. cerasifera (cherry plum), particularly in early spring when the latter starts flowering somewhat earlier thanP. spinosa.[citation needed] They can be distinguished by flower colour, pure white inP. spinosa, creamy white inP. cerasifera. In addition, thesepals are bent backwards inP. cerasifera, but not inP. spinosa.[9] They can be distinguished in winter by the shrubbier habit with stiffer, wider-angled branches ofP. spinosa; in summer by the relatively narrower leaves ofP. spinosa, more than twice as long as broad;[5][10][page needed] and in autumn by the colour of the fruit skin purplish black inP. spinosa and yellow or red inP. cerasifera.[11]: 207
Prunus spinosa has atetraploid (2n=4x=32) set of chromosomes.[12]
Like many other fruits withpits, the pit of the sloe contains trace amounts ofhydrogen cyanide.[13]
The specific namespinosa is a Latin term indicating the pointed and thornlikespur shoots characteristic of this species. The common nameblackthorn is due to the thorny nature of the shrub, and possibly its very dark bark: it has a much darker bark than the white-thorn (hawthorn), to which it is contrasted.[14]
P. spinosa is native to Europe, western Asia, and locally in northwest Africa.[5][17] It is also locallynaturalized inTasmania and eastern North America.[17]
The shrub, with its long, sharp thorns, is traditionally used in Britain and other parts of northern Europe to make a cattle-proofhedge.[18]
The fruit is similar to a smalldamson orplum, suitable for preserves, but rathertart andastringent for eating fresh unless it is picked after the first few days of autumn frost. This effect can be reproduced by freezing harvested sloes.[19]
Since the plant is hardy, and grows in a wide range of conditions, it is used as arootstock for many other species of plum, as well as some other fruit species.[citation needed]
The juice is used in the manufacture of fakeport wine, and it was used as anadulterant to impart roughness to genuine port, into the 20th century.[20][21][22] In rural Britain aliqueur,sloe gin, is made by infusinggin with sloes and sugar;vodka can also be infused with sloes.[23] Similarly, inNorthern Greece, they make a blackthorn liqueur by infusingtsipouro with the fruit and adding sugar.[citation needed]
InNavarre, Spain, a popular liqueur calledpacharán is made with sloes.[citation needed] In France a liqueur calledtroussepinette, or justépine orépinette, is made from the young shoots in spring (rather than from fruits in autumn).[citation needed] (Vin d'épine, likewise, is an infusion of early shoots of blackthornmacerated with sugar in wine.)[24][25] InItaly, the infusion of spirit with the fruits and sugar produces a liqueur calledbargnolino (sometimesprunella).[citation needed] In France,eau de vie de prunelle[s] is distilled from fermented sloes in regions such as theAlsace.[b] Wine made fromfermented sloes is made in Britain, and inGermany and other central European countries.[citation needed] It is also sometimes used in the brewing oflambic beer inBelgium.[citation needed]
Sloes can also be made intojam,chutney,[23] and used in fruit pies. Sloes preserved invinegar are similar in taste toJapaneseumeboshi. The juice of the fruits dyes linen a reddish colour that washes out to a durable pale blue.[18]
The leaves resemble tea leaves, and were used as an adulterant of tea.[21][28]
Thefruit stones have been found in Swiss lake dwellings.[21] Early human use of sloes as food is evidenced in the case of a 5,300-year-old humanmummy (nicknamedÖtzi), discovered in theÖtztal Alps along the Austrian-Italian border in 1991: a sloe was found near the remains, indicating that Ötzi intended to eat it before he died.[29][30]
Blackthorn makes an excellentfire wood that burns slowly with a good heat and little smoke.[31] The wood takes a fine polish and is used for tool handles and canes.[28] Straight blackthorn stems have traditionally been made intowalking sticks orclubs (known inIreland as ashillelagh).[32] In the British Army, blackthorn sticks are carried by commissioned officers of theRoyal Irish Regiment; this is a tradition also in Irish regiments in someCommonwealth countries.[citation needed]
The expression "sloe-black eyes" for a person with dark eyes comes from the fruit,[36] and is first attested inWilliam Somervile's 1735 poemThe Chace.[37]sloe-eyed, meanwhile, is first attested inA. J. Wilson's 1867 novelVashti.[38]
The flowering of the blackthorn may have been associated with the ancient Celtic celebration ofImbolc, traditionally celebrated on February 1 in Ireland, Scotland and the Isle of Man.[39]
The name of the dark-coloured clothprunella was derived from the French wordprunelle, meaning 'sloe'.[40]
^Brown, Lynda (July 1994)."Damson time".House & Garden. Vol. 166. pp. 140–142, esp. 142 – via Google Books.In former times people waited to pick the sloes until the first frost which makes the skins more permeable ... [A proprietor] which makes one of the best sloe gins, recommends freezing the fruit first.
Ehrlén, Johan; Eriksson, Ove (1991). "Phenological variation in fruit characteristics in vertebrate-dispersed plants".Oecologia.86 (4):463–470.doi:10.1007/BF00318311.ISSN0029-8549.
Weinberger, J.H. (1975). "Plums". In Janick, J.; Moore, J.N. (eds.).Advances in Fruit Breeding. West Lafayette, IN:Purdue University Press. pp. 336–347.ISBN0-911198-36-9.
