Morphological variability of the tallow tree, Pentadesma butyracea Sabine (Clusiaceae), in Benin

Abstract

The seeds of Pentadesma butyracea (butter tree) are exploited by rural populations in West Africa to produce butter used for consumption and as an ingredient in cosmetics and medicinal preparations. To improve our knowledge of this under-studied species, the morphological variation of the trees, fruits and seeds in 12 natural populations of Benin distributed over a gradient of climate aridity is described with 14 quantitative and 13 qualitative descriptors. Most traits, except seed shape categories, show significant differences among populations. Multivariate analyses distinguish two eco-geographical groups: trees located in the more humid southern part of the species distribution are taller and have larger fruits and seeds than trees located in the north. To disentangle the relative roles of genetic variation and phenotypic plasticity in shaping, further phenotypic studies should be performed in common garden experiments.