Prunus spinosa of the fruit caused by the fungus "Taphrina pruni" produces an elongated and flattened gall, devoid of a stone. The shrub, with its savage thorns, is traditionally used in Britain and other parts of northern Europe to make a "cattle-proof" hedge. The fruit is similar to a small damson or plum, suitable for preserves, but rather and for eating, unless it is picked after the first few days of autumn frost. This effect can be reproduced by freezing harvested sloes. The juice is used in the manufacture of fake port wine, and used as an to impart roughness to genuine
Prunus subg. Padus "Padus" is polyphyletic and is therefore invalid as a genus, subgenus or anything else. In Finland and Sweden, the blooming of bird cherry ("Prunus padus", Finnish "tuomi") signifies the start of the summer for many people. In southern Finland, this normally takes place during the two last weeks of May or very early June. North Dakota State University agriculture information page about "Prunus virginiana" Prunus subg. Padus Prunus" subg. "Padus (bird cherries) is a subgenus of "Prunus", characterised by having deciduous leaves, flowers 12-30 together on slender racemes produced in late spring well after leaf emergence, and small, sour fruit