The genus Cinnamomum

Table 2.6 Microscopic characteristics of barks of four Cinnamomum spp.
1 2 3 4 5
Microscopic C. verum C. camphora C. tamala C. iners
characters
(a) Phellem 5–10 layers – thin-walled, 5–20 layers – tangentially 10–20 layers – two kinds of 10–15 layers – slightly
tangentially flattened, elongated cells, slightly cork cells alternating each suberised; contain
suberised cork cells suberised other which are either reddish-brown substance
suberised or sclerosed
(b) Phellogen Not distinct Not distinct More or less distinct due Somewhat distinct
to presence of brownish
content
(c) Phelloderm Not sharply defined from Several layers of cells which 16–20 layers of tangentially Several layers of tangentially
pericyclic region. 10–16 contain either starch grains elongated cells that either elongated cells that contain
layers of tangentially that are sparingly distributed; contain starch grains or starch grains, acicular
elongated cells that contain contain acicular crystals of acicular crystals of calcium crystals and a few prismatic
either starch grains or filled calcium oxalate oxalate crystals of calcium oxalate
with a brownish substance
(d) Secretory Cells containing oil are Distributed in the cortical Distributed in the cortical Few cells containing
cells intermingled with cortical and phloem region which and phloem region. These essential oils and mucilage
parenchyma cells and some contain oil cells contain oil, mucilage in the cortical and pericycle
containing oil and large cells and tannin regions
containing mucilage are
scattered in the phloem
region
(e) Stone cells Middle part of the bark Distributed in the cortical Distributed in the outer Stone cells are separated by
contains tangentially region, isolated or in groups, region of the cortex cortical parenchyma cells
elongated, sometimes associated with fibres, thick walled with pitted walls and slightly
thick-walled sclerenchymatous generally thick walled with thickened at one side. A few
stone cells with reduced their walls striated are occasionally found in
cavities. Inner walls thicker the bast region
than outer
(f) Half stone Present Absent Present Present
cells