Comparative study of the tracheary elements of the three species of Pittosporum

Tracheary elements, particularly their secondary wall thickening and perforation plates were studied and compared in three species of Pittosporum (P. pentandrum (BI.) Merr., P. resiniferum Hemsl., and P. moluccanum Lamk). Mature root, steam and leaf (midrib and petiole) were macerated using Modified Jeffrey\u27s Method (1940). Tracheary elements in P. pentandrum (BI.) Merr. were helical and scalariform in both root and steam. In P. resiniferum Hemsl. leaf petiole and midrib had helical and scalariform helical, scalariform and pitted in stem had scaliform, pitted and helical, and roots with pitted only. Only a simple type of perforation plate was observed in vessels