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Botanical Aspects of Cereals
Grasses
Cereals are cultivated grasses that grow through-
out the temperate and tropical regions of the
world. As members of the Gramineae (or grass
family) they share the following characteristics,
but these are developed to different degrees in
the various members:
Vegetative features of grasses
1. Conspicuous nodes in the stem.
2. A single leaf at each node.
3. Leaves in two opposite ranks.
4. Leaves consist of sheath and blade.
5. Tendency to form branches at nodes and
adventitious roots at the bases of nodes.
6. Lower branches may take root and develop
into stems as tillers.
Variation in vegetative features among species
may be illustrated by reference to maize and
wheat. In wheat branches occur only at the base
of the main stem or culm, to produce tillers (Fig. The pattern of branching The
) (Percival, 1921). While all tillers have the in the wheat plant. pattern of
branching
capacity to bear ears, the later formed ones may in the maize
not actually do so; this habit is characteristic of plant
most cereals.
In maize branches occur higher on the main among cereals in that, on the branches, only the
stems and they are much shorter as the internodes ans develop in the florets and on the
do not extend (Fig. ). main culm only ans develop. The advent-
Leaf bases are very close together and the leaves itious roots that develop at the base of the main
consist almost entirely of blades which surround stem provide support for the aerial parts of the
the inflorescence, and the shortness of its stalk plant (Ennos, 1991); in maize they are called
leads to branches that are almost entirely inflore- prop-roots and they are particularly well developed
scence. At the tip of the main culm there is also as is appropriate to the large and heavy nature of
an inflorescence as in wheat, but maize is unique the aerial parts.
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30 TECHNOLOGY OF CEREALS