The genus Cinnamomum

Botany and Crop Improvement of Cinnamon and Cassia 51
divisions producing two superposed tiers of cells (pc and pc). They undergo further
divisions and finally lead to the formation of the central cylinder of the stem and cotyledons
and the hypocotyledonary region, respectively. The two daughter cells of the basal
cell (bc) divide transversely giving rise to two superposed tiers of cells. The upper tier
divides further in all planes and forms the hypophyseal region. The lower tier gives rise
to the suspensor. The epiphyseal cell undergoes further divisions, ultimately forming
the stem apex.
Since the derivatives of the apical cell of the two-celled proembryo alone contribute
to the formation of the embryo proper, while the suspensor and hypophyseal regions are
derived from the basal cell, the embryo development is of Onagraceae type.
Endosperm
ca
cb
1 2 3
e
7
10
e
e
e
pc
pc′
e
4
8 9
11
m
ei
e e
12
5 6
Figure 2.16 Stages in the development of embryo (for explanations see text). ca – apical cell; cb –
basal cell; e – epiphyseal initial; pc, pc – tiers of cells derived from subepiphyseal cells;
m – hypophyseal initial, that divides and forms the hypophyseal region; ci – suspensor
initial that eventually gives rise to the suspensor. (Source: Sastri, 1958.)
The primary endosperm nucleus divides earlier than the fertilised egg. Endosperm
development is of the nuclear type (Sastri, 1958). By the time the zygote undergoes the
first division, eight to ten free nuclei derived from the division of the endosperm nucleus
are seen distributed along the periphery of the embryosac. These nuclei are large with
one to three nucleoli. The endosperm nuclei have glistening crystalline bodies at the
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