Agriculture Reference
In-Depth Information
a masculinization of the crop. In this last case,
the plants demonstrate both male and female
characteristics: the male flower appearing
towards the middle of the stem, the apical part
supporting the female inflorescence (Bocsa and
Karus, 1997).
The male flowers are composed of five
greeny-yellow sepals enclosing five tightly
packed stamens that open to reveal little
anthers (Fig. 3.1). The female flower is easily
distinguished from the male. Devoid of petals,
this female flower is made up of two pistils and
a single seed pod. The pistils measure on
average between 3 and 8 mm in length and are
enclosed by a small sheath, or bract, that is
then attached to the stem. The bracts bear the
highest density of trichrome glands and it is
these that are responsible for the production of
cannabinoids in those varieties rich in THC.
These structures are also found on the leaves,
although at a lower concentration, together
with non-glandular trichomes that do not
produce cannabinoids.
The seed
This commonly used term is inappropriate
from a botanical point of view. The ovule pro-
duces an indehiscent fruit (akene) in which the
seed (embryo) takes up all the volume. This
seed is enveloped in its own coat (testa) and
outer envelope (pericarp). Hemp seeds are
ovoid or spherical in shape and measure
3-5 mm in length depending on the cultivar.
Each grain encloses two cotyledons rich in oil
and proteins but, unlike many other plant spe-
cies, these seeds contain a reduced quantity of
albumen. Although hemp is not grown specifi-
cally for the purposes of oil production, the
yield from certain monoecious varieties allows
the industrial exploitation of hemp seeds for oil.
The stem
Regardless of the cultivar, the general morphol-
ogy of the stem remains similar. The internode
distance between branches can vary. The surface
Fig. 3.1.
Male and female inflorescences and the corresponding details of their respective flowers.
(a) Male flower; (b) female flower.
