Comparative wood anatomy of some members of the genus Caesalpinia (Linn.) Sw
The wood anatomy of two varieties of Caesalpinia bonduc (L.) Roxb., that is the staminate and pistillate plants and four varieties of Caesalpinia pulcherrima (Linn).Sw, namely, Red, Yellow, Off-white and Pink petal plants were studied in search of wood anatomical characters that may be useful in the taxonomy of the Caesalpinia genus. Transverse, tangential longitudinal and radial longitudinal sections of the woods were made and some other parts of the woods were macerated. Qualitative and quantitative characters were observed and measured respectively, in all the taxa. The data were subjected to Duncan multiple range test (DMRT), principal components analysis (PCA) and single linkage cluster analysis (SLCA). The results revealed that growth ring is absent in all the taxa studied. They all have diffuse porous woods with heterogenous, uniseriate rays and solitary vessels. Pistillate plant of C. bonduc is the only taxa with multiple ray cells. Apotracheal axial parenchyma type was unique to the staminate plant of C. bonduc while paratracheal type was unique to C. bonduc pistillate. All the varieties of C. pulcherrima lack axial parenchyma. Tylose was absent in the pistillate plant of C. bonduc var. female and C. pulcherrima var. pink but present in all the other taxa. The first three components of the PCA accounted for 95.73% of the total variation among the taxa. It was concluded that quantitative and qualitative wood anatomical characters can be employed in differentiating the species and varieties of Caesalpinia studied.
Keywords: Axial parenchyma, Caesalpinia, Fibres, Tylose, Vessels, Wood anatomy