Trees are boring. All they do is stand there, occasionally looking pretty in the winter or dropping fruit in the autumn. Except trees are fascinating organisms. They live on a timescale that is hard to relate to human life, and because they act so slowly we often do not notice what they are doing. Here are ten particularly unusual trees; unusual either because of their biology or because humans have changed them in some way.

10.
Sculpted Trees



Arborsculpture is the use of living trees to create a desired shape or structure, something like bonsai on a grand scale. Axel Erlandson is considered the greatest of all arborsculptors and his ‘Circus trees’ are still popular attractions. Through directing the growth of the tree while alive, it is also possible to create unique pieces of furniture by harvesting the wood once it takes on the desired form. While Erlandson’s work, seen here (http://www.arborsmith.com/treecircus.html), is the most commonly cited when arbor sculpture is discussed, there are many living practitioners.

8.
Dragon Blood Tree



The Socotra Archipelago in the Indian Ocean, off the coast of Somalia, is home to the Dragon Blood tree. The Dragon Blood tree is unusual for a number of reasons. Its trunk is bare and branches only at the top, ending in sharp spiky leaves. This unusual appearance is due to the Dragon Blood tree belonging to the monocotyledons, the same group of plants as grasses, rather than dicotyledons, which are more common amongst trees. As well as an unusual exterior, the trees also reveal an unusual interior; once pierced bright red sap oozes out. The crimson sap, called Dragon Blood, is dried and then used as a medicine or a dye. While the inhabitants of Socotra still use it as a panacea, the sap is mostly used in the West as a red varnish for violins.

6.
Pennantia baylisiana



What is special about this tree? It looks just like many other trees and does not do anything particularly exciting. This tree is unusual in the literal sense of uncommon as it is, in fact, the rarest tree we know of in the wild. There is a single example of this tree in the Three Kings Islands off the north coast of New Zealand. Since the lone example of the tree is female there is no hope of breeding more. In cases of self-pollination the fruit are almost always sterile. Luckily, however, it is possible to detach shoots and culture them so the species can now be found in several places, but for true survival of the species it would be advantageous to locate a male Pennantia baylisiana.