Buxus sempervirens L. (Buxaceae).
Box is most widely known to us nowadays as a formal hedging plant, or clipped closely into myriad other shapes. Sadly, in the mid-1990s, box blight began to ravage the box hedging of the United Kingdom. This fungal disease, caused by two different pathogens (Cylindocladium buxicola and Volutella buxi), results in the dieback of box foliage and sometimes even of the young shoots, causing unsightly bare patches. Unfortunately there are no fungicides available to amateur gardeners that are specifically recommended for control of box blight, although others recommended for use on ornamentals can be legally, if not successfully, used.
Whether or not Buxus sempervirens is a native species of the British Isles is a surprisingly contentious issue, and there is no agreement on the answer. Those who argue that it is indigenous point to the naming of Box Hill in Surrey which has a population of Buxus trees growing on it; there have also been archaeological finds of Roman graves in England with Buxus sempervirens leaves thrown in, suggesting that they have been present in the British Isles for some time. On the other hand, the herbalist John Parkinson drew a distinction between 'Buxus humilis' (Buxus sempervirens) and 'our common Boxe tree', saying that the former was found only in gardens and that the latter was common in woodland. So, is Buxus sempervirens native to the British Isles or not? The best answer may well be the one expressed by one recent group of authors: 'its native status is uncertain'.
It would appear that Buxus was not really considered as a medicinally useful plant in the 1600s. Parkinson said that 'it is not much used in Physicke by any now adayes' but he does describe a medicine made of Buxus leaves that he 'learned of a friend, who had tryed it effectuall' which could 'cure the biting of a mad dogge'. However, in the centuries since, many substances have been isolated from this species with a wide range of biological activities including acetylcholinesterase activity, which renders it potentially useful as an Alzheimer's treatment.
While it was not traditionally used in medicine, Buxus was not entirely useless. It became highly regarded for making woodcuts to illustrate books, a technique developed in the eighteenth century by engraver and author Thomas Bewick. It is a very close-grained wood, possibly the hardest and most dense wood of any tree found commonly growing in Europe.
Decocq G et al 2004. A practical approach to assess the native status of a rare plant species: the controversy of Buxus sempervirens L. in northern France revisited. Plant Ecology 173, 139-151.