PCA of Cites Listed Pterocarpus Santalinus (Leguminosae) Wood

Abstract

Pterocarpus santalinus L. f. is endemic to south eastern India where it is known as ‘red sandal wood’ or ‘red sanders wood’. A highly valued timber for its structural and medicinal properties P. santalinus is listed under CITES Appendix II, reflecting the possibility of extinction should unregulated trade continue. Currently timber identification uses comparative wood anatomy. Some P. santalinus specimens are very distinct from closely related species, but this is not always the case. PCA was applied to data on 17 wood anatomical characters and one physical character of several Pterocarpus species including P. santalinus. A comparative description of P. santalinus is presented using the same data as PCA. The primary quantitative outcome was discrete clustering of P. santalinus in PCA axes scores plots, distinguishing it from the other included species. PCA eigenvector data indicated which characters were responsible for the greatest amount of variance in the data set. With simple modifications PCA has considerable potential in quantitative wood anatomy as a complementary technique to comparative wood anatomy for the identification of cryptic wood specimens.