Morphological Variability of Pterocarpus erinaceus Poir. in Togo

Pterocarpus erinaceus Poir. (Fabaceae), also called Vene or West African rosewood, is a multipurpose endemic forest species of Sahelo-Sudanian and Sudano-Guinean savannas and forests of West Africa. In Togo, the species is overexploited, which dangerously hinders its survival. The need and emergency of restoring declining stands, using seeds, or propagating material suggests an assessment of its morphological variability. The purpose of this study is to identify the discriminating morphological descriptors, allowing us to describe and also to characterize the species. Five provenances distributed over the whole geographical distribution area in Togo were evaluated for leaf (7 descriptors), fruit (4 descriptors), and seed (4 descriptors) traits. The coefficient of variation (CV) and the principal component analysis (PCA) are used to assess the variability among tree populations. Results show that the discriminating morphological descriptors for P. erinaceus in Togo are the width of the leaf and the terminal leaflet, the length and the width of the fruit, and length and the weight of the seed. These six main relevant variables allow us to discriminate three morphological groups of P. erinaceus population.