<em>Machaerium acutifolium</em> complex morphometry

The neotropical jacarandá species of the Machaerium acutifolium complex (Leguminosae, Papilionoideae) are among the most widely distributed in the genus, occurring in six countries of South America, where it displays great ecological and economic importance. Across its distribution in almost all Brazilian biomes, M. acutifolium presents an evident phenotypic plasticity, mainly in the shape and size of the leaflets, that led to the description of different taxonomic entities over the years. However, the significant morphological variation observed within the complex’s species prompts consideration for further studies. Here, we re-evaluate the taxonomic delimitation within the M. acutifolium species complex using morphometric and bioclimatic data. A nomenclatural review and morphological assessment of M. acutifolium and related species were carried out to support the PCA morphometric analyses of 23 vegetative and 27 reproductive characters, from a total of 99 specimens as well as eco-geographic features of 131 specimens.