Blackberry bush and Bramble bush

Blackberry bush noun - Bramble with sweet edible black or dark purple berries that usually do not separate from the receptacle.

Bramble bush and blackberry bush are semantically related. In some cases you can use "Bramble bush" instead a noun phrase "Blackberry bush".

Bramble bush noun - Any prickly shrub of the genus Rubus bearing edible aggregate fruits.

Blackberry bush and bramble bush are semantically related. Sometimes you can replace phrase "Blackberry bush" with "Bramble bush", this phrases are similar.