The brambles are a notoriously complex group within the European flora. In the British Isles alone, over 300 bramble (micro-)species are recognised, and new microspecies are constantly being added to the British list. Most botanists find it very difficult to differentiate the microspecies, which are simply referred to as the Rubus fruticosus aggregate. In 1912, Jason White, author of the Bristol Flora, made the point eloquently; 'it needs … abundant leisure and enthusiastic diligence to make a botanist familiar with this intricate, but fascinating genus; as well as that gift of pertinacity which will save him from discouragement, both when his diagnoses prove faulty and when the names he has become accustomed to are discarded or reshuffled, in deference to changed views in high places either at home or abroad'.
The complexities of bramble identification are associated with the subtlety of the characters used for microspecies differentiation, and the absence of critical characters on all individuals of a microspecies. Reliable bramble identification means visiting the same plant on numerous separate occasions, and they are difficult to collect. Furthermore, the reproductive systems of brambles mean offspring share most of their characters with their female parent. Moreover, microspecies are capable of hybridisation. Despite such difficulties, and perhaps because of them, generations of professional and amateur botanists have been attracted to brambles. Bramble specialists are called batologists, from the ancient Greek name for blackberry.
Most people who come across brambles have few concerns about which microspecies they are harvesting for fruit or cursing as weeds. People who regularly collect blackberries in the wild get to know where the best bushes are to be found. The flavour and form of bramble fruits depends on growth conditions and microspecies. As a weed, many bramble microspecies colonise areas by producing runners, that is stem when root when their tips touch the ground.
In the early twentieth century, the botanical artist Charlotte Trower began illustrating British brambles in collaboration with a leading pre-First World War batologist, the Reverend William Moyle Rogers. Trower set her sights high when she chose as her model the illustrations in Carl Weihe and Christian Nees's Rubi Germanica (1822-27). Rogers, whilst appreciating Trower's talent, was highly critical; he considered only about one in four of her illustrations suitable. Eventually, Trower finished 38 watercolours and black ink drawings of British brambles, for which she was awarded a Grenfell Silver-gilt Medal by the Royal Horticultural Society.
Edees ES and Newton A 1988. Brambles of the British Isles. Ray Society.
Harris SA 2009. The Trower collection: Botanical watercolours of an Edwardian lady. Journal of the History of Collections 22: 115-128.
Sell P and Murrell G 2014. Flora of Great Britain and Ireland. Volume 2 Capparaceae - Rosaceae. Cambridge University Press, pp. 146-318.