Blackberry bushes look similar to raspberry plants. Identifying blackberry bushes requires inspection of the shape of the bush, the leaves and the fruit. For close inspection, wear protective clothing and eye wear since the blackberry has thorns.
Inspect the shape of the bush
Look for large, dense, rambling bushes. Blackberry bushes have arching canes that grow up to 40 feet long. Once they reach maturity, they tend to droop to the ground. When they touch the ground, they form roots and create new plants. This creates a thicket of briars that may be impassable.
Inspect the leaves
Turn over the leaf of a blackberry bush and examine the spine. The spine has a row of thorns running along it. The top of the leaf is dark green and has white fuzz growing on it. Leaflets come in sets of three to five arranged around a center ridge.
Inspect the fruit
The fruit of a blackberry bush consists of a cluster of droops. Changing from white in the early spring to red as they mature, and finally becoming a deep purple, the blackberry is best identified when picked. Blackberries retain the core when picked, while raspberries are hollow, leaving the core behind.