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 pumila leathery, long, with a serrated margin. The flowers are in diameter with five white petals and 25–30 stamens. They are produced in small clusters of two to four. The fruit is a small cherry diameter, ripening dark purple in early summer. "Prunus × cistena" (purple leaf sand cherry) is a hybrid of "Prunus cerasifera" (Cherry Plum) and "Prunus pumila". It was developed by Niels Ebbesen Hansen of South Dakota State University in 1910. Prunus pumila Prunus pumila, commonly called sand cherry, is a North American species of cherry in the rose family. It is widespread in eastern and central Canada