Wood Anatomy of Selected West African Species of Caesalpinioideae and Mimosoideae (Leguminosae): A Comparative Study

Abstract

Leguminosae constitute an important proportion of the charcoal sampIes recovered at archaeological sites in the West African savannas. Identification of these fragments to a level below family or subfamily was problematic, because a comparative survey was missing. Therefore, the wood anatomy of 31 species (23 genera) of Mimosoideae and Caesalpinioideae growing in the Sudanian savannas of West Africa was examined. The species were grouped into 18 types according to wood anatomical structure. The types represent single species or genera (fourteen types), two genera (three types) or three genera (one type) . The following features are regarded as suitable for a reliable delimitation and identification . Heterocellular rays and storied structure allow for a first differentiation. Enlarged, non-bordered vessel-ray pitting , nonvestured vessel-pits, silica, axial canals, septate fibres and crystals in non-eharnbered ray cells are additional features characterizing few or single types. Types without these features are delimited less easily. Parenchyma distribution and ray width are, due to variability, not as reliable , but remain necessary features for identification. Types characterized by these features only may not always be recognized correctly. Quantitative features of the vessels are not regarded as helpful for the differentiation within the set of examined species. A table (Table 1) summarizes the results for easy reference.