Vestured pits of Combretaceae and allied families

The structural variation of vestures in bordered pits, with special reference to Combretaceae, is described and classified. Two major types of vesturing are recognized: Type A, in which the vestures are attached to all parts of the roof of the pit chamber and branch into a mass of vestures of equal thickness; and type B, in which vestures with a trunk-like base are attached to the roof of the pit chamber nearby the pit canal, and branch to various extents into thinner vestures. I n type B three forms are recognized, based on the degree of branching of the vestures, and on the relative thickness of the trunks (cf.fig. I). The diagnostic and systematic value of the major forms is restricted because of the occurrence of intermediates between them and because of infrageneric variation in Terminalia. However, the major types of vesturing follow the subfamily classification of the Combretaceae: type A in Strephonematoideae and type B in Combretoideae. The variation in structure and distribution of warts and vestures is described and discussed. Morphological intermediates are suggestive of a homology of warts and vestures, contrary to conclusions based on limited ontogenetic research in the literature. The differences in wart development and vestures around the apertures in different vessel contact areas (inter-vessel, vessel-ray, and vesselaxial parenchyma) are also described and discussed.