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 ursina It is usually present in too small a quantity to do any harm but any very bitter seed or fruit should not be eaten. Consumption of small quantities of hydrogen cyanide stimulates respiration and improves digestion. Excessive consumption of the toxin can cause respiratory failure and death. "Prunus ursina" fuits better in full sun but is still successful in partial shade. The tree will form suckers if its shallow roots are damaged. Among the pests that affect the "prunus" genus is honey fungus. the seed requires 2–3 months cold stratification in order to germinate. Prunus ursina Prunus ursina (bear's plum,