Variability of vessel characteristics in the xylem of Ilex paraguariensis (mate-tree) from South Brazil

In this study the wood anatomy of two leaf-morphotypes ("Yellow" and "Grey") of Ilex paraguariensis St. Hil. (Aquifoliaceae) from South Brazil was compared with special attention to vessel attributes and a possible relationship of leaf morphology and wood structure. Sampling was carried out in a 15-year-old plantation in the state of Parand, South Brazil. The anatomy of the juvenile and mature wood of five male and five female plants of each morphotype was investigated by light microscopy. In all plants the increment and the proportion of vessels decreased from pith to cambium, while vessel element length increased. Plants of the morphotype "Grey" had shorter vessel members (157-382 mum) and a lower number of bars per perforation plate (14-15) compared to the plants of the morphotype "Yellow" (vessel member length: 304-567 mum, bars: 22-24). No significant differences were found between the wood of male and female plants.