WOOD ANATOMY OF THE BRAZILIAN SPECIES OF SWARTZIA AND CONSIDERATIONS WITHIN THE TRIBE SWARTZIEAE

Abstract

Fifty-one Brazilian species and varieties of Swartzia Schreber and eight other genera from the tribe Swartzieae were examined. Features with the greatest diagnostic value for the tribe are intervascular pit size, ray width and frequency, storied structure, axial parenchyma strand length, parenchyma band width, and vessel diameter. We analyzed the wood anatomical data using average linkage cluster analysis and canonical discriminant analysis. With weighted features, cluster analysis grouped the species and varieties of Swartzia into four distinct groups and tribe Swartzieae into seven groups. With unweighted features for both Swartzia and Swartzieae, the canonical discriminant analysis showed that linear combinations of the variables storied structure, number of tiers per millimetre, axial parenchyma strand length, ray height, intervascular pit size, and exclusively uniseriate rays were good discriminators among the groups. We discuss the grouping of the species of Swartzia and compare other genera within the tribe Swartzieae to the four groups of Swartzia.