Prunus spinosa Prunus spinosa Prunus spinosa, called blackthorn or sloe, is a species of flowering plant in the rose family Rosaceae. It is native to Europe, western Asia, and locally in northwest Africa. It is also locally naturalised in New Zealand, Tasmania and eastern North America. "Prunus spinosa" is a large deciduous shrub or small tree growing to tall, with blackish bark and dense, stiff, spiny branches. The leaves are oval, long and broad, with a serrated margin. The flowers are about in diameter, with five creamy-white petals; they are produced shortly before the leaves in early spring, and are hermaphroditic and
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