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 americana Prunus americana Prunus americana, commonly called the American plum, wild plum, or Marshall's large yellow sweet plum, is a species of "Prunus" native to North America from Saskatchewan and Idaho south to New Mexico and east to Québec, Maine and Florida. "Prunus americana" has often been planted outside its native range and sometimes escapes cultivation. It is commonly confused with the Canada plum ("Prunus nigra"), although the fruit is smaller and rounder and bright red as opposed to yellow. Many cultivated varieties have been derived from this species. It forms an excellent stock upon which to graft the domestic plum.