DALBERGIA CONGESTIFLORA STANDL - WOOD STRUCTURE AND PHYSICOCHEMICAL PROPERTIES COMPARED WITH OTHER CENTRAL-AMERICAN SPECIES OF DALBERGIA

Wood structure and selected physico-chemical properties of a rare Mexi can species, tentatively identified as Dalbergia congestiflora, are de scribed and compared with other Central American species of Dalbergia. On account of their distinct wood structure, four species groups can be distinguished: 1) D. granadillo, D. hypoleuca, D. lineata and D. re tusa ('cocobolo') are characterised by mainly apotracheal diffuse-in-a ggregates parenchyma, large and few vessels, high density (0.89-1.35 g /cm(3)), identical heartwood colour, and chemical composition of extra ctives (D. granadillo, D. retusa); 2) D. tucuruensis (including D. cub ilquitzensis) and D. palo-escrito are identical in all aspects but dis tinct from the cocobolo group on account of differences in parenchyma distribution, heartwood colour and extractives composition (D. tucurue nsis), and the consistently lower density (less than or equal to 0.80 g/cm(3)); 3) D. congestiflora and D. funera (= D. calderonii) differ m arkedly in heartwood colour and somewhat in heartwood extractives comp osition but share a high density and similar wood structural pattern c haracterised primarily by relatively small and frequent vessels, bande d parenchyma and the presence of prismatic crystals in ray cells; 4) D . stevensonii is very similar in wood structure to D. tucuruensis but has a much higher density and different heartwood extractives composit ion. These results indicate that the combination of wood structure and chemistry of heartwood extractives may be successfully employed for i ntrageneric classification of Dalbergia.