Wood anatomy and topochemistry of Bombax ceiba L. and Bombax insigne wall

Wood anatomical characteristics, content of phenolic extractives, and topochemistry of two lesser known and underutilized hardwood species, Bombax ceiba and Bombax insigne were studied. Heartwood and sapwood material was obtained from logs originating from natural forests of Pyinmana District, Myanmar. The basic qualitative anatomical features agreed with descriptions reported for the species in other regions (i.g. India, Bangladesh, Southeast Asia). However there were some light differences in the quantitative wood anatomical data among the regions due to the influence of environmental conditions. The amount of phenolic extractives obtained by gradual extraction with acetone-water was almost the same in heartwood and sapwood (about 1,2%) in B. insigne, while heartwood showed a higher amount (2,8%) than sapwood (2,5%) in B. ceiba. Topochemical distribution of lignin and phenolic deposits in heartwood tissues investigated by scanning UV microspectrophotometry (UMSP) revealed that B. insigne is more highly lignified than B. ceiba. For both species, a lower UV-absorbance by the fiber and ray cell wall as compared to that of the cell wall of vessels was observed. Also, phenolic compounds were mostly deposited in the lumina of parenchyma cells and vessels rather than in cell walls. The results further improve the knowledge on the wood anatomy and chemistry of the species and in this respect are useful in future research to broaden their utilisation potential