Agriculture Reference
In-Depth Information
3
Physiology and Botany
of Industrial Hemp
Brigitte Chabbert
1
(Part I), Bernard Kurek
1
(Part II) and
Olivier Beherec
2
(Part III)
1
INRA, France;
2
FNPC, France
3.1 Introduction
this dicotyledenous angiosperm is somewhat
controversial. Various taxonomic approaches
have been called upon. Where morphological
criteria were applied, hemp was placed initially
in the order
Urticacea
. Recent molecular
studies have, however, produced a new phylo-
genic classification of the flowering plants
(
Angiospermae
). This reclassification of the
dicotyledons into distinct orders is based on
the characterization of common molecules
(such as the
Rubisco
genes). Thus, according
to Chase (1998), the
Cannabaceae
family is
now to be found in the order
Rosales
, which,
together with six other orders, form the sub-
class
Rosidae
. A number of other fibre-rich
plants, including flax and ramie (
Boehmeria
nivea
) are also to be found in this subclass. The
Cannabaceae
family is considered to form
a single genus Cannabis comprised of the
species
Cannabis sativa
L., that itself regroups
three subspecies (Bocsa and Karus, 1997):
In order to do justice to the complex subjects
of hemp physiology and botany, researchers
Brigitte Chabbert and Bernard Kurek, of the
Institut National de la Recherche Agronomique
(INRA), France, present the plant's anatomy
and botany, together with its chemical compo-
sition and properties.
Building on this first part, Olivier Beherec
then presents and details the particularities and
specificities of the plant's vegetative cycle.
3.2 Hemp Physiology
This section is presented in two parts:
•
Anatomy and botany
•
Constituents and chemical composition.
3.3
Part I: Anatomy and Botany
1.
C. sativa
corresponds to industrial hemp
and is the source of phloem fibres.
2.
C. ruderalis
is the wild form.
3.
C. indica
L. is characterized by a high
content of tetrahydrocannabinol (THC), the
principal cannabinoid of hemp.
More recently, a distinction has been made
between the two species in the Cannabis
genus. It is proposed that
C. indica
L.
and
C. sativa
L. be designated two separate
3.3.1
Classification and botanical
description
Hemp was one of the first crops to be grown
for the production of natural fibre. Today, this
annual plant grows under a wide range of
climatic conditions, but is principally found
growing in Europe and Asia. The taxonomy of
