If you want to know the difference between a bramble and a blackberry, you’ll find various definitions online:

• A bramble is a blackberry and vice versa.
• Blackberry is the fruit and bramble the bush.
• Bramble is wild (Rubus vulgaris) and blackberry (Rubus fruiticosus) is cultivated.
• Bramble is the northern name and blackberry the southern.
• A bramble is any rough, tangled, prickly shrub, usually in the genus Rubus.
• Some people combine the two to specify the type of fruit: blackberry bramble, raspberry bramble, loganberry bramble.

The answers seem plausible to a greater or lesser degree, and geography will influence what sounds right to you. As a northern British speaker, I use them like this:

• I picked and ate a wild blackberry (= the fruit; could also be a cultivated berry)
• I tripped over a bramble (= a long, prickly cane)
• The rabbit hid in a blackberry bush (= the whole plant)

I’d use bramble as a generic folk name for the whole plant if I wanted an earthy, rural term or did not need to specify the type of fruit.

There are over 330 bramble species in the UK, some highly localised. These plants were growing on moorland and had unusually bright red autumn foliage that caught the sunlight beautifully.

Foragers will be aware that some wild blackberry bushes produce larger, sweeter fruit than others. The botanical name for the cultivated variety of blackberries (Rubus fruiticosus) should be the most reliable indication of sweetness, but I’ve sometimes found wild berries as sweet as any – and being wild gave their sweetness extra pleasure.