Abstract: The vessel elements of secondary xylem in Manilkara zapota were observed by bio-microscope
image analysis system and micrography. There were various patterns of vessel elements in M. zapota and most
of the vessel elements had tail. Perforation p lates could be divided into two types: 1. Both ends of the vessel
element were simp le perforation p late; 2. One end had simple perforation, the other had two simp le perfora
tions. And there were a series of transitional patterns between the two types. Three percent of vessel elements
of secondary xylem in the p lant had inclusions. Intervascular p itting was alternate p itting. There were mixed
type p itting, gash-like p itting and perforation between vessel elements and ray cells.

Key words: Manilkara zapota, Vessel elements, Perforation plate, Conformation and structure