The genus Cinnamomum

Botany and Crop Improvement of Cinnamon and Cassia 41
Figure 2.9b Nature of cinnamon bark. 1. A cinnamon stem (branch). 2–4. Diagrammatic sketches of
transverse sections of the bark from three regions: 2. base of the branch, 3. middle of the
branch, 4. top of the branch. 5a. T.S. of stem tip at region indicated. 5b. T.S. of bark from the
region indicated. bf – phloem fibre; f – fibre; kl – cork layer; m – pith; mr – medullary ray;
muc – mucilage cell; oc – oil cell; ph – phloem; sc – sclereid; st – stone cell; xy – xylem.
(Source: Namba et al., 1987.)
view (Fig. 2.10). The characteristic features of cassia bark powder are very similar to cinnamon,
distinguishable by the larger size of starch granules, the greater diameter of
fibres and the abundance of cork fragments. In the case of cinnamon, starch granules are
rarely over 10 m in diameter, fibres up to 30 m in diameter. In the case of cassia
single starch granules are more than 10 m in diameter and fibres are up to 40 m in
diameter (Fig. 2.11). Brief descriptions on bark and bark powder characteristics are also
given by Parry (1969) and Wallis (1967).
Bark regeneration
Cassia bark is extracted from standing trees (in Vietnam and some parts of China) and
fast bark regeneration is very important. No effort has so far been made to improve the
bark regeneration after bark removal. Hong and Yetong (1997) have shown that application
of a bark regeneration fluid followed by wrapping with plastic film resulted in
80% regeneration of bark and such bark is thicker with higher oil and cinnamaldehyde
contents. The composition of the regeneration fluid is not known.