- The shorter and larger cystolith-containing conical trichomes (Fig.5.3h, i),
which are about 50– 125 μm long with a large base measuring about 60– 140 μm
in diameter. These trichomes are found mainly on the adaxial surface of the
leaves. About 15–20 epidermal cells form a circle around the base of the tri-
chomes. These trichomes, with their enlarged base and shortly pointed tip,
appear like a‘claw’. - The longer and slender trichomes (Figs.5.2e, f;5.3a), which are about 250–
370 μm long and are abundantly distributed on the abaxial leaf surfaces, stems,
petioles and tepals.
The non-glandular trichomes are generally pointed towards the apices of leaves
or stems. The trichomes located on or near the major veins have a warty surface
whereas those occurring between the veins have slightly warty or smooth surface
(Jiang et al. 2006 ). Silica (SiO 2 .nH 2 O) is reported to be distributed more or less
evenly all over these trichomes (Dayanandan and Kaufman 1976 ). The enlarged
basal part of the cystolith trichome contains large crystal of calcium carbonate
(CaCO 3 ) (Fig.5.3i). They are prominent in the trichomes found on the adaxial leaf
surface. Few trichomes containing cystolith crystals are also found on the abaxial
leaf surface, stem and petiole. Calcium (Ca) is mainly deposited in the form of
CaCO 3 in the cystolith, but small amount of Ca may also be present throughout the
inner cavity of the trichomes (Dayanandan and Kaufman 1976 ).
Both glandular and non-glandular trichomes are present in both pistillate and
staminate plants and they are found inCannabisplants from the early seedling stage
to maturity. The capitate-stalked glandular trichomes are found only in the bracts of
pistillate plants and anthers in the staminate plants (Dayanandan and Kaufman
1976 ). Bulbous and capitate-sessile glandular trichomes occur on all parts of
vegetative andflowering shoots except for the hypocotyl and cotyledons whereas
capitate-stalked glands are restricted toflowering regions of the plants. Bracts have
the highest concentration of glandular trichomes than any other part on pistillate
plants (Hammond and Mahlberg 1973 ). The capitate-stalked glands are found only
in theflowering bracts in pistillate plants. In staminate plants, this trichome type is
restricted only to longitudinal rows along the inner surfaces of anthers (Dayanandan
and Kaufman 1976 ).
5.4 Anatomy
Cannabishas been associated with human since ancient times, however, little is
known about its comparative anatomy (Anderson 1974 ). Tippo ( 1938 ) made few
general comments on the wood ofC. sativa, and Nassonov ( 1940 ) discussed about
stem shape and leaf trace number in transections in his work on geographical
races of hemp. He stated that wild and cultivated forms of hemp could not be
differentiated clearly based on anatomy of stem and bastfibers. Hayward ( 1938 )
studied general morphology, seedling anatomy and floral structure of hemp.
130 V. Raman et al.