A symbolic framework for the description of tree architecture models

The system of tree architecture proposed by Hallé and Oldeman consists of 23 models named after botanists playing leading roles in elucidating tree architecture. This system gives no indication why other models do not occur. A symbolism is presented here which can serve as a shorthand in recording tree architectures without assumptions about models. and immediately interpretable. Using this symbolism to represent the models proposed by Hallé and Oldeman permits creation of general rules of tree architecture. some of which raise interesting theoretical questions. Two further tree models that might well be expected to exist and several which would not be expected. are described.