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 phylo­ genetic analyses ofrelationships in flowering plants. However, the re­ sults ofa cladistic analysis are only as good as the characters and obser­ vations, 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 ofwood 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 ofillus­ trating some common problems and their possible solutions, we con­ clude with a brief discussion of recent cladistic analyses that have includedwoodanatomicalcharacters.