The genus Cinnamomum

44 P.N. Ravindran et al.
Table 2.7 Xylem anatomical features of C. camphora and C. porrectum
Features C. camphora C. porrectum
Pore distribution (% per group)
Solitary 51 30
Multiple 40 63
Cluster 9 7
Perforation Scalariform Simple scalariform
Pore diameter (range ) 41–95 68–136
Vessel element length (range ) 150–462 204–639
Fibres Fibre-tracheid Septate, fibriform wood fibres
Parenchyma Terminal, vasicentric Vasicentric
Source: Stern, 1954.
thin-walled, vessel element end wall inclination 30°–50°, mostly 45°, intervascular
pits circular to oval. Pitting alternate with some opposite, vascular rays heterogeneous,
one to three cells wide, uniseriate rays uncommon; one to six but mostly two to three
cells high, multiseriate rays 4–17 mostly 7–14 cells high; secretory cells in rays, axial
parenchyma present and all inclusions occur as idioblasts; sclerotic pith flecks present.
Xylem anatomical features of C. camphora in comparison with C. porrectum are given in
Table 2.7.
Floral morphology, biology and breeding behaviour
Flowers of cinnamon are produced in lax terminal or axillary panicles that are almost
equal to or slightly longer than the leaves. The flowers are abundant with long greenish
white peduncles. The flowers are softly hairy, bracteate, actinomorphic, bisexual,
trimerous, perigynous, perianth six in two whorls of three each, free, stamens 9 3 in
four whorls of three each; outer two whorls introrse and glandless, third whorl extrorse
and flanked by two prominent glands, fourth whorl is represented by glandless, sagittate,
stalked staminodes. Fertile stamens show valvular dehiscence. The filaments of
stamens and staminodes are provided with minute hairs. Ovary superior, unilocular
with a single pendulous anatropous ovule. Style long, ending in a stigma which belongs
to dry, papillate class (Heslop-Harrison and Shivanna, 1977) (see Fig. 2.2).
Joseph (1981) and Kubitzsky and Kurz (1984) and Mohanakumar et al. (1985) have
studied the floral biology but information is still incomplete. Flowering starts by
November and lasts until the early part of March. On average, flower development
takes 14 days from the stage of its visible initiation (Fig. 2.12a). The female and male
phases are separated temporally (protogynous dichogamy) thereby ensuring outcrossing.
Protogynous dichogamy leads to the maturing of the female phase first, and the
male phase later. The two phases are separated by almost a day, during which time the
flower closes completely.
Joseph (1981) reported that every flower opens twice in two stages. In stage one on
the first day, when a flower opens, its stigma is whitish and fresh and appears to be
receptive. There is no anther dehiscence, and the stamens of the first whorl and those
of the third whorl appear fused. After about five hours the flower closes. In stage two,
the next day, the flower opens again. The stigma by then appears shrivelled and not