Field and Morphometric Studies of Phyllobotryon Müell.Arg. (Salicaceae) in the Korup Forest Area of Cameroon

Morphometric analysis of Phyllobotryon Müell.Arg. in the Korup Forest Area of Cameroon recognizes three distinct morphospecies (1-3), which show significant variation in several leaf and fruit characters. In order to clarify the taxonomy of Phyllobotryon, we conducted univariate and multivariate analyses on sixteen quantitative and four qualitative characters scored from 111 fresh samples. Analysis of Variance revealed nine significant quantitative characters from which the first three Principal Components accounted for 74.6 % of the total variation. Results from Discriminant Analysis strongly support the existence of two groups (96.2 % and 100 %) representing Morphospecies 2 and 3, but morphospecies 2 is only weakly supported (88.9 %) as distinct from morphospecies 1. Characters such as petiole length, fruit surface ornamentation, style & calyx persistence, flower and fruit orientation and leaf shape are of taxonomic importance. A comparison of our three morphospecies to literature descriptions and available herbarium specimens matched up our morphospecies 1 to the published Phyllobotryon spathulatum Müell.Arg., while the two other morphospecies did not correspond to validly published taxa. Based on our results, the analyzed morphological variation suggests three morphological entities and one known species in the genus, and therefore a formal taxonomic status of the species rank should be considered for all three morphospecies. An identification key to taxa of the genus is provided.