Black Raspberry is a medium-sized woody shrub, usually growing to a height of 5 to 8 feet and forming dense thickets. Its egg-shaped leaves are alternate and compound, with three leaflets per leaf stalk. Leaf stalks are mostly smooth with a few straight prickles. Its arching stems are up to 12 feet long, covered with slightly curved to downward-angled prickles. Black Raspberry is monoecious. Starting in Mid-May, clusters of 5 to 15 white flowers form at the tips of lateral branches. The berries are purple to black round clusters about ½” in diameter that contain dozens of seeds and ripen beginning in July.
Black Raspberry fruits have been recorded in the diets of over 150 species of birds and mammals that disperse them considerable distances from the parent plant. The dense thickets the plant forms provide shelter for rabbits, foxes, chipmunks, snakes, young deer, and many other animals.
Black Raspberry grows best along forest edges, powerline corridors, oak savannas, and in other areas that are partially sunny and partially shady. Black Raspberry has a high tolerance of a variety of pH conditions, but it prefers well-aerated soil on dry sites.
In the Arb:
Look for Black Raspberry in cleared areas and along roadsides, such on the path into the Lower Arb across from the Arboretum Office. Other places to look for it are in the brushy, former farmer’s fields just to the east of Best Woods.