Comparative Structure Of Vascular Cambium And Its Derivatives In Some Species Of Sterculia

Abstract

Structural variations in cambium, xylem and phloem collected from main trunks of Sterculia colorata, S. alata, S. villosa, S. urens and S. foetida growing in the South Dangs forests were studied. In all five species, the cambium was storied with variations in the length of fusiform cambial cells. Compared to other species S. foetida had the longest and S. urens the shortest fusiform cambial cells. Cambial rays in all the species were compound (tall) and heterocellular with sheath cells. Their height and width were maximal in S. foetida and in S. villosa respectively. In all the species the storied nature of fusiform cambial cells was maintained in derivative cells that developed into sieve tube elements; vessel elements and axial parenchyma of both phloem and xylem. However, fibres of phloem and xylem were nonstoried. The dimensions of elements in phloem and xylem varied among the species. The variation in the mean length of sieve tube elements and vessel members coincided with that of fusiform cambial cells.