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 simonii is particularly aromatic, much more so than "Prunus salicina", with a comparatively high level of hexyl acetate, which gives apples their aroma. Plant breeder Luther Burbank devoted a lot of work to hybridizing this species with the Japanese plum ("Prunus salicina") and developed a number of cultivars from the hybrid. Of these, the cultivar 'Climax' was particularly notable for its importance to the fruit shipping industry of California. Other influential plum cultivars that Burbank developed with "P. simonii" ancestry include 'Maynard', 'Chalco', 'Santa Rosa', and 'Formosa'. Those two species and the European species "Prunus cerasifera" have contributed the majority of