2 Botanical Aspects of Cereals Gras Cereals are cultivated grasses that grow througl out the temperate and tropical regions of the orld. As members of the gramineae (or grass amily) 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 Branching 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 node 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 FIG 2. 1 The pattern of branching 2.1)(Percival, 1921). While all tillers have the in the wheat plant ttern of capacity to bear ears, the later formed ones may branching not actually do so; this habit is characteristic of most cereal In maize branches occur higher on the main among cereals in that, on the branches, only the tems and they are much shorter as the internodes female organs develop in the forets and on the do not extend(Fig. 2.2) main culm only male organs 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 infore prop-roots and they are particularly well develope cence.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 parts2 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. 2.1) (Percival, 1921). While all tillers have the capacity to bear ears, the later formed ones may not actually do so; this habit is characteristic of most cereals. In maize branches occur higher on the main stems and they are much shorter as the internodes do not extend (Fig. 2.2). Leaf bases are very close together and the leaves consist almost entirely of blades which surround the inflorescence, and the shortness of its stalk leads to branches that are almost entirely inflore￾scence. At the tip of the main culm there is also an inflorescence as in wheat, but maize is unique FIG 2.1 The pattern of branching in the wheat plant. FIG 2.2 The pattern of branching in the maize plant among cereals in that, on the branches, only the female organs develop in the florets and on the main culm only male organs develop. The advent￾itious roots that develop at the base of the main stem provide support for the aerial parts of the plant (Ennos, 1991); in maize they are called prop-roots and they are particularly well developed as is appropriate to the large and heavy nature of the aerial parts. 29