Utility of wood anatomical characters in cladistic analyses

Wood anatomy is an important source of systematically informative character information that can and should be used in cladistic phylogenetic analyses of relationships in flowering plants. However, the results of a cladistic analysis are only as good as the characters and observations, which together comprise the data set that is analyzed. The goal of this paper is to address the former of these issues, specifically the definition and use of wood anatomical characters in cladistic analyses. We first provide a brief introduction to the principles of cladistics. We then discuss the standard IAWA List of wood anatomical characters, which are defined primarily for identification, and recast them in a format that is more appropriate for cladistic analysis. As a means of illustrating some common problems and their possible solutions, we conclude with a brief discussion of recent cladistic analyses that have included wood anatomical characters.