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 maximowiczii leaves of "P. maximowiczii" are green; and those from the fruit, a dark grey to green. Chemically, amygdalin and prunasin, the derivatives of which produce prussic acid as well as Genistein can be extracted from "P. maximowiczii". Prunus maximowiczii Prunus maximowiczii, known as Korean cherry, Korean mountain cherry, or Miyama cherry, is a small (about 7.5 m), fruiting cherry tree that can be found growing wild in northeastern Asia and Eurasia. The species was first described in 1857 by Franz Josef Ruprecht. It was treated in the genus "Cerasus" (now generally accepted as a subgenus of "Prunus") by Vladimir Leontyevich