Fig. 3

Scanning electron microscopy showing variation in the structure of vessel-to-parenchyma pits in the inner side of vessel wall in Afzelia bipindensis. Adjacent areas of two cells (vessel elements) in the same vessel (a) The pits in the upper vessel element have abundant vestures (a, b) while the pits in the lower vessel element have few or no vestures (a, c) An enlarged view from the upper vessel element (b) An enlarged view from the lower vessel element (c) Bars: 20 µm (a); 2 µm (b); 5 µm (c)