A Handbook of Some South Indian Grasses — Inside the Classic

Grasses occupy wide tracts of land and they are evenly distributed in all parts of the world. They occur in every soil, in all kinds of situations and under all climatic conditions. In certain places grasses form a leading feature of the flora. As grasses do not like shade, they are not usually abundant within the forests either as regards the number of individuals, or of species. But in open places they do very well and sometimes whole tracts become grass-lands. Then a very great portion of the actual vegetation would consist of grasses.

On account of their almost universal distribution and their great economic value grasses are of great importance to man. And yet very few people appreciate the worth of grasses. Although several families of plants supply the wants of man, the grass family exceeds all the others in the amount and the value of its products. The grasses growing in pasture land and the cereals grown all over the world are of more value to man and his domestic animals than all the other plants taken together.

To the popular mind grasses are only herbaceous plants with narrow leaves such as the hariali, ginger grass and the kolakattai grass. But in the grass family or Gramineæ the cereals, sugarcane and bamboos are also included.

Grasses are rather interesting in that they are usually successful in occupying large tracts of land to the exclusion of other plants. If we take into consideration the number of individuals of any species of grass, they will be found to out-number those of any species of any other family. Even as regards the number of species this family ranks fifth, the first four places being occupied respectively by Compositæ, Leguminosæ, Orchideæ and Rubiaceæ.

As grasses form an exceedingly natural family it is very difficult for beginners to readily distinguish them from one another.

The leaves and branches of grasses are very much alike and the flowers are so small that they are liable to be passed by unnoticed. The recognition of even our common grasses is quite a task for a botanist.

To understand the general structure of grasses and to become familiar with them it is necessary to study closely some common grasses. We shall begin our study by selecting as a type one of the species of the genus Panicum.

_Panicum javanicum_ is an annual herb with stems radiating in all directions from a centre. The plant is fixed to the soil by a tuft of fibrous roots all springing from the bases of the stems. In addition to this crown of fibrous roots, there may be roots at the nodes of some of the prostrate branches. The stems and branches are short at first, and leaves arise on them one after the other in rapid succession. After the appearance of a fair number of leaves the stem elongates gradually and it finally ends in an inflorescence.

The stem consists of =nodes= and =internodes=. The internodes are cylindrical and somewhat flattened on the side towards the axillary bud. When young they are completely covered by the leaves and the older ones have only their lower portions covered by the leaf-sheaths. Usually they complete their growth in length very soon, but the lower portion of the internode, just above the node and enclosed by the sheath, retains its power of growth for some time.

The leaf consists of the two parts, the =leaf-sheath= and the =leaf-blade=. At the junction of these two parts there is a very thin narrow membrane with fine hairs on its free margin. This is called the =ligule=. (See fig. 2.)

The leaf-sheath is attached at its base to the node and it is slightly swollen just above the place of insertion. It covers the internode, one margin being inside and the other outside. The surface of the sheath is sparsely covered with long hairs springing from small tubercles. The outer margin of the sheath bears fine hairs all along its length. (See fig. 2.)