A Handbook of Some South Indian Gra.s.ses.

by Rai Bahadur K. Ranga Achariyar and C. Tadulinga Mudaliyar.

PREFACE

This book is intended to serve as a guide to the study of gra.s.ses of the plains of South India. For the past few years I have been receiving gra.s.ses for identification, almost every week, from the officers of the Agricultural and Forest Departments and others interested in gra.s.ses.

The requirements of these men and the absence of a suitable book induced me to write this book.

I have included in this book about one hundred gra.s.ses of wide distribution in the plains of South India. Many of them occur also in other parts of India. The rarer gra.s.ses of the plains and those growing on the hills are omitted, with a view to deal with them separately.

The value of gra.s.ses can be realized from the fact that man can supply all his needs from them alone, and their importance in agriculture is very great, as the welfare of the cattle is dependent upon gra.s.ses.

Farmers, as a rule, take no interest in them, although profitable agriculture is impossible without gra.s.ses. Very few of them can give the names of at least half a dozen gra.s.ses growing on their land. They neglect gra.s.ses, because they are common and are found everywhere. They cannot discriminate between them. To a farmer "gra.s.s is gra.s.s" and that is all he cares to trouble himself about. About gra.s.ses Robinson writes "Gra.s.s is King. It rules and governs the world. It is the very foundation of all commerce: without it the earth would be a barren waste, and cotton, gold, and commerce all dead."

In the early days when the population was very much limited and when land not brought under cultivation was extensive plenty of green gra.s.ses was upon it and pastures were numerous. So the farmer paid no attention to the gra.s.ses, and it did not matter much. But now, population has increased, unoccupied land has decreased very much and the cattle have increased in number. Consequently he has to pay more attention to gra.s.ses.

On account of the scarcity of fodder, people interested in agriculture and cattle rearing have very often imported foreign gra.s.ses and fodder plants into this country, but so far no one has succeeded in establis.h.i.+ng any one of them on any large scale. Usually a great amount of labour and much money is spent in these attempts. If the same amount of attention is bestowed on indigenous gra.s.ses, better results can be obtained with less labour and money. There are many indigenous gra.s.ses that will yield plenty of stuff, if they are given a chance to grow. The present deterioration of gra.s.ses is mainly due to overgrazing and trampling by men and cattle.

To prove the beneficial effects which result from preventing overgrazing and trampling, Mr. G. R. Hilson, Deputy Director of Agriculture (now Cotton Expert), selected some portion of the waste land in the neighbourhood of the Farm at Hagari and closed it for men and cattle. As a result of this measure, in two years, a number of gra.s.ses and other plants were found growing on the enclosed area very well, and all of them seeded well. Of course the unenclosed areas were bare as usual.

In the preparation of this book I received considerable help from M.R.Ry. C. Tadulinga Mudaliyar Avargal, F.L.S., a.s.sistant Lecturing and Systematic Botanist, in the description of species and I am indebted to M.R.Ry. P.S. Jivanna Rao, M.A., Teaching a.s.sistant, for a.s.sistance in proofreading.

I have to express my deep obligation to Mr. G. A. D. Stuart, I.C.S., Director of Agriculture, for encouragement to undertake this work and to the Madras Government for ordering its publication.

For the excellence in the get up of the book I am indebted to Mr. F. L.

Gilbert, Superintendent, Government Press.

K. RANGACHARI.

AGRICULTURAL COLLEGE, LAWLEY ROAD, COIMBATORE, _2nd June 1921._

CHAPTER I.

INTRODUCTION.

Gra.s.ses 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 gra.s.ses form a leading feature of the flora. As gra.s.ses 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 gra.s.s-lands. Then a very great portion of the actual vegetation would consist of gra.s.ses.

On account of their almost universal distribution and their great economic value gra.s.ses are of great importance to man. And yet very few people appreciate the worth of gra.s.ses. Although several families of plants supply the wants of man, the gra.s.s family exceeds all the others in the amount and the value of its products. The gra.s.ses 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 gra.s.ses are only herbaceous plants with narrow leaves such as the hariali, ginger gra.s.s and the kolakattai gra.s.s. But in the gra.s.s family or Gramineae the cereals, sugarcane and bamboos are also included.

Gra.s.ses 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 gra.s.s, 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 Compositae, Leguminosae, Orchideae and Rubiaceae.

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

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

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

_Panic.u.m javanic.u.m_ 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.

[Ill.u.s.tration: Fig. 1.--Panic.u.m javanic.u.m. (Full plant.)]

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 spa.r.s.ely covered with long hairs springing from small tubercles. The outer margin of the sheath bears fine hairs all along its length. (See fig. 2.)

The leaf-blade is broadly lanceolate, with a tip finely drawn out. Its base is rounded and the margin wavy, especially so towards the base. On the margin towards the base long hairs are seen, and some of these arise from small tubercles. The margin has a hyaline border which is very minutely serrate. There is a distinct midrib and, on holding the leaf against the light, four or five small veins come in to view. In the s.p.a.ces between these veins lie many fine veins. All the veins run parallel from the base to the apex. At the base of the blade the veins get into the leaf-sheath and therefore the sheath becomes striated. Just above the ligule and at the base of the leaf-blade there is a colourless narrow zone. This is called the =collar=.

[Ill.u.s.tration: Fig. 2.--Leaf of Panic.u.m javanic.u.m.

A. Full leaf; B. a portion of the leaf showing 1. the ligule and 2. the collar.]

As already stated the inflorescences appear at the free ends of branches. Every branch sooner or later terminates in an inflorescence which is a compound raceme. There are usually five or six racemes in the inflorescence. Each raceme has an axis, called the =rachis=, which bears unilaterally two rows of bud-like bodies. These bud-like bodies are the units of the inflorescence and they are called =spikelets=. (See fig.

3.)

[Ill.u.s.tration: Fig. 3.--The inflorescence of Panic.u.m javanic.u.m.

1. Inflorescence; 2 and 3. the front and the back view of a raceme.]

The spikelets are softly hairy and are shortly stalked. The pedicels of spikelets are hairy and sometimes one or two long hairs are also found on them. Each of these spikelets consists of four green membranous structures called =glumes=. The first two glumes are unequal, the first being very small. The second and the third glumes are broadly ovate-oblong with acute tips. Both are of the same height and texture, but the second is 7-nerved and the third 5-nerved. The fourth glume is membranous when young, but later on it becomes thick, coriaceous and rugose at the surface. Just opposite to the fourth glume there is a flat structure with two nerves, similar to the glume in texture. This is called the =palea=. The fourth glume and its palea adhere together by their margins. Inside the fourth glume and between it and the palea there are three stamens and an ovary with two styles ending in feathery stigmas. Just in front of the ovary and outside the stamens two very small scale-like bodies are found. These are the =lodicules=. They are fleshy and well developed in flowers that are about to open. In the spikelet there is only one full flower. The third glume contains no flower in it, but occasionally there may be in its axil three stamens.

The first two glumes are always empty and so they are called empty glumes. (See fig. 4.) In mature spikelets the grain which is free is enclosed by the fourth glume and its palea.

[Ill.u.s.tration: Fig. 4.--Parts of the spikelets of Panic.u.m javanic.u.m.

A. A spikelet; 1, 2, 3 and 4. the first, second, third and the fourth glume, respectively; 3a. palea of the third glume; 4a. palea of the fourth glume; 5. lodicules; 6. stamens; 7. ovary; 8. stigmas.]

CHAPTER II.

THE VEGETATIVE ORGANS.

Gra.s.ses vary very much in their habit. Some gra.s.ses grow erect forming tufts and others form cus.h.i.+ons with the branches creeping along the ground. (See figs. 5 and 6.) We usually find all intermediate stages from the erect to the prostrate habit. Underground stems such as stolons and rhizomes occur in some gra.s.ses. Gra.s.ses of one particular species generally retain the same habit but this does not always hold good. For example _Tragus racemosus_ grows with all its branches quite prostrate in a poor, dry, open soil. If, on the other hand, this happens to grow in rich soils, or amidst other plants or gra.s.ses, it a.s.sumes an erect, somewhat tufted habit. _Andropogon contortus_ and _Andropogon pertusus_ are other gra.s.ses with a tendency for variation in habit. Plants that are usually small often attain large dimensions under favourable conditions of growth. Ordinarily the gra.s.s _Panic.u.m javanic.u.m_ grows only to 1 or 2 feet. (See fig. 1.) The same plant in a good rich soil grew to about 6 feet in four months. (See fig. 7.)

[Ill.u.s.tration: Fig. 5.--Eleusine aegyptiaca.]

Some gra.s.ses are annual while others are perennial. It is often difficult to determine whether a certain gra.s.s is annual or perennial.

But by examining the shoot-system this can be ascertained easily. In an annual all the stems and branches usually end in inflorescences and they will all be of the same year. If, on the other hand, both young leafy branches and old branches ending in inflorescences are found mixed, it must be a perennial gra.s.s. The presence of the remains of old leaves, underground stolons and rhizomes is also evidence showing the perennial character of the plant.