Prunus spinosa the more shrubby habit with stiffer, wider-angled branches of "P. spinosa"; in summer by the relatively narrower leaves of "P. spinosa", more than twice as long as broad; and in autumn by the colour of the fruit skin purplish black in "P. spinosa" and yellow or red in "P. cerasifera". "Prunus spinosa" has a tetraploid (2"n"=4"x"=32) set of chromosomes. The specific name "" is a Latin term indicating the pointed and thornlike spur shoots characteristic of this species. The common name "" is due to the thorny nature of the shrub, and its very dark bark. The word commonly used
Prunus × pugetensis The chief difference from its parents is that its flowers almost always abort, and it rarely bears any fruit. Prunus × pugetensis Prunus × pugetensis is a hybrid species of cherry discovered growing in the Pacific Northwest region of North America. It has been given the nominal common name Puget Sound cherry. It is a cross of introduced sweet cherry, "Prunus avium", and native Oregon cherry, "Prunus emarginata". Individuals have been found growing in British Columbia, Washington state and Oregon, in the natural range of "P. emarginata". It differs from "P. avium" in a number of features, including having narrower