Brambles form a complex group known as Rubus fruticosus agg. (short for aggregate), containing around 320 individual 'species' known as microspecies (3). These varieties are very difficult to tell apart (1). All brambles are sprawling shrubs, with thick prickly stems that are able to take root at their tips (2). The leaves have toothed edges and bear prickles on their undersides (2). The flowers tend to be creamy white with splashes of pink, and the unmistakable blackberries are a deep purplish-black when ripe (4). Microspecies differ on the basis of certain morphological features, including the density and arrangement of the prickles, and general growth form (5).