They are also found in the UK and western Europe, where they are often used as hedge plants. The berries are actually clusters of drupes, containing the hard seeds that stick in our teeth when we eat them. When the shrubs lack the woody fibers in their stems that permit them to stand erect, and are instead trailing by nature, they're called dewberries . Some of these also produce excellent fruits and some are cultivated. I think I have run across a few specimens in my woods of one of the more common, weedy types, Rubus flagellaris , the northern dewberry, but I won't swear to it.
Flowers are typically white, although some are pink or even red.
They generally are simple, with five petals - much like wild roses. Flowering is in late spring, with fruit ripening from late summer through fall. While brambles will grow in shade, they won't flower or fruit well without some sun. In good conditions, they can be very aggressive, forming impenetrable thickets. They spread by bird and mammal sown seed, root sprouts, rhizomes and tip layering.