Prunus spinosa insect-pollinated. The fruit, called a "sloe", is a drupe in diameter, black with a purple-blue waxy bloom, ripening in autumn and harvested – traditionally, at least in the UK – in October or November after the first frosts. Sloes are thin-fleshed, with a very strongly astringent flavour when fresh. "Prunus spinosa" is frequently confused with the related "P. cerasifera" (cherry plum), particularly in early spring when the latter starts flowering somewhat earlier than "P. spinosa". They can be distinguished by flower colour, creamy white in "P. spinosa", pure white in "P. cerasifera". They can also be distinguished in winter 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