Prunus and Pliny uses "prūnus silvestris" to mean the blackthorn. The word is not native Latin, but is a loan from Greek προῦνον ("prounon"), which is a variant of προῦμνον ("proumnon"), origin unknown. The tree is προύμνη ("proumnē"). Most dictionaries follow Hoffman, "Etymologisches Wörterbuch des Griechischen", in making some form of the word a loan from a pre-Greek language of Asia Minor, related to Phrygian. The first use of "Prunus" as a genus name was by Carl Linnaeus in "Hortus Cliffortianus" of 1737, which went on to become "Species Plantarum". In that work, Linnaeus attributes the word to "Varr.", who it
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