They also point out that the
middle zone is the one where most of the bamboo
exhibits the largest vascular bundles. However,
in G. angustifolia the largest appear in the inner
zone. The length of the different zones varies with
the species, the diameter and the thickness of the
culm’s wall. Generally, the external third of the
culm’s wall is formed by the periphery and by
the transition zone (Grosser and Liese, 1971).
In G. angustifolia, these two zones only represent
15% of the wall’s thickness, which has a
significant influence on the ultimate composition
of the culm. The concentration of vascular
bundles varies depending on the zone. In G.
angustifolia the periphery and transition zone
have the largest amount of vascular bundles per
unit of area (346-530 vb cm-2) followed by the
middle one (81-194 vb cm-2) and inner zones
(52-96 vb cm-2) (Fig.7; Table 2).