Prunus spinosa the British Army, blackthorn sticks are carried by commissioned officers of the Royal Irish Regiment; this is a tradition also in Irish regiments in some Commonwealth countries. The leaves resemble tea leaves, and were used as an adulterant of tea. Shlomo Yitzhaki, a Talmudist and Tanakh commentator of the High Middle Ages, writes that the sap (or gum) of "P. spinosa" (which he refers to as the ) was used as an ingredient in the making of some inks used for manuscripts. The fruit stones have been found in Swiss lake dwellings. Evidence of the early use of sloes by
Prunus × cistena Prunus × cistena Prunus × cistena, the purple leaf sand cherry or dwarf red-leaf plum, is a hybrid species of prune-cherry, the result of a cross between "Prunus cerasifera" (cherry plum or myrobalan plum) and "Prunus pumila" (sand cherry). A leggy bush or shrubby tree, it typically reaches a height of 1.5–2.5 meters and has a useful life of 10–20 years. The fruit are edible, if strong-tasting. Some people make jams or preserves from them. It is not advisable to eat the pits. Frost-tolerant, purple leaf sand cherries can be grown up to USDA Hardiness Zone 2. Commercial specimens are