Rubus pensilvanicus, commonly known as Pennsylvania blackberry, is a prickly bramble native to eastern and central North America from Newfoundland. It is a shrub that can grow up to 10 feet tall. The canes are green initially but turn dark red, usually ridged, with copious straight prickles.

The leaves are palmately compound, usually bearing 5 or 7 leaflets. The flowers are white with large petals and bloom in mid-spring. The fruits are large aggregates of 10 – 100 black druplets, somewhat sweet, and often used for jams and jellies.

Source: Wikipedia.