COMPARATIVE WOOD ANATOMY OF ROOT AND STEM IN STYRAX-CAMPORUM (STYRACACEAE)

Styrax camporum Pohl is a shrub common in the cerrado vegetation of so uth-eastern Brazil. Root and stem wood in Styrax camporum differ quant itatively and qualitatively. Quantitative differences follow normal ex pectations: roots have wider and longer vessel elements, a lower vesse l frequency, a lower ray frequency, and wider rays. Qualitative featur es of the roots are: simple perforation plates, vestured pits, and sep tate libriform fibres; qualitative features of the stems are: multiple perforation plates, non-vestured pits, and non-septate fibre-tracheid s. Based on generally accepted evolutionary trends, root wood of Styra x camporum has more specialized features than stem wood. Additional co mparative studies of stem and root anatomy are needed to determine if such differences between root and stem anatomy are widespread, and con sistent with the lines of specialization observed in monocotyledons.