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 rivularis Prunus rivularis Prunus rivularis, known variously by the common names creek plum, hog plum, or wild-goose plum is a thicket forming shrub. It prefers calcareous clay soil or limestone-based woodland soils. This deciduous plant belongs to the rose family, Rosaceae, and is found mainly in the central United States. It is a shrub consisting of slender stems with umbel clusters of white blossoms. The fruit is a drupe that resembles a large berry; though it has a bitter taste, it serves as a source of food for birds and other wildlife. ""Prunus"" is Latin for plum, whereas ""rivularis"" means being