Ktêsias, the Knidian, who wrote a treatise on India about four hundred years before Christ, speaks of reeds growing there, of “a height to equal the mast of a merchant ship of the heaviest burden”. This is believed to be the earliest European reference to the tribe of the Gramineae called Bambuseae, or bamboos. It seems to have been long before any exact knowledge of these “reeds” penetrated to the West, for there is little notice of them by European writers, between Pliny and the sixteenth-century herbalists, who make some slight allusion to them; Jerome Bock in 1552, for instance, mentions reeds which “in India…in arboream magnitudinem excrescunt”. The origin of the name bamboo is obscure. It may possibly be a trade corruption of the Malay word ‘Samámbu’, used for the Malacca-cane. Though the bamboo meant nothing to Western civilisation in early days, its extreme importance to the peoples of tropical countries is reflected in the position which it occupies in their folk-lore. It is said, for instance, that the Kings of Boeton—a small island near Celebes—claimed that they sprang originally from a giant bamboo. The story ran that in old days, when the people of Boeton had no king, a man entered the forest to fell bamboos for his own use. He was just attacking a fine stem, when a voice cried, “Man! do not destroy my foot, but insert your axe a little higher; I am in bondage here”.

It is now more than thirty years since, at my suggestion, Ethel Sargant sowed the grains of wheat and maize which formed the starting-point of work upon the grass seedling which we did together. Before her death in 1918, I had turned to a more general examination of the monocotyledons; but in course of time I began to feel that it might be possible to get a clearer view of the questions arising out of this study, if I combined it with more intensive work upon some one of the great monocotyledonous orders. With this in view, I returned to the Gramineae, and for the last ten years they have seldom been far from my thoughts. My concern with them was at first purely morphological, but, as I came to visualise the nexus of problems presented by the life of bamboo and grass, as well as by the history of the cereals—so inextricably interwoven with the history of man—these wider fields began to fascinate me almost as much as the more limited and technical facies of my own special studies.

The grasses are a vast group, and a correspondingly vast mass of information about them has been accumulated by botanists. If this information were brought together and correlated, it would form a library rather than a volume. In the present book I have had no such encyclopaedic aim, but I have deliberately limited myself to those aspects of the subject which happen to make the greatest appeal to me personally.

In the branch systems of grasses, each lateral shoot bears a bikeeled first leaf (prophyll) facing the axillant leaf and addorsed to the main axis (Fig. 182, B, p. 356). Opinion has been divided, in the past, as to whether this bikeeling indicates a derivation from two leaves, but the more recent evidence seems to me to favour the view that the prophyll is a single leaf, whose characters are those of a leafsheath. It probably owes its curious form to the pressure due to space conditions in the bud. Although the prophyll has two principal bundles, its symmetry is not really duplex, for one of the bundles is, as a rule, earlier in development, and larger, than the other. Moreover the bud axillary to the prophyll tends to occur opposite to this larger strand, which may thus, on all counts, be interpreted as the median bundle. These points are illustrated in Fig. 142, p. 280, and Fig. 143, A2 a−A2 c. p. 281. In one or more of the earliest leaves succeeding the prophyll, the sheath is apt to predominate, while the limb is absent or reduced (cf. Fig. 131, A, p. 265).

The mode of origin of the leaf members from the stem apex in grasses is a matter of some interest. A few years ago, it was reported that in Wheat the leaves develop from the dermatogen alone, whereas, in other families, not only the dermatogen, but deeper layers as well, play a part in leaf production.

The grass family is remarkable both for its naturalness and for its distinctness from neighbouring groups. Though other families have sometimes been included with it in the order Glumales or Glumiflorae, the most recent tendency is to treat it as a group apart, and to regard the resemblances which it shows, for instance, to the Sedge family (Cyperaceae), as indicating parallel development rather than affinity. If this view be accepted, I should like to suggest that the established word Gramineae might be retained for the order; the name Graminaceae could then perhaps be used for the only family included in this order.

Within the group itself, classification presents special difficulties; the subdivisions have even been described as “complétement artificielles”. The species are very numerous—they are estimated as 8000, or even more, grouped in about 550 genera—and their structural characteristics do not lend themselves to any obvious classificatory scheme. Indeed, as Kunth wrote, more than a hundred years ago, “dans les families eminemment naturelles, comme celles des Graminées, … on ne trouve que très-peu de caractères … qui puissent servir à distinguer les genres, et le plus souvent ces caractéres sont aussi vagues que minutieux”. In classifying the grasses, botanists have thus been obliged to rely, even more than usual, upon that intuitive faculty for detecting affinities, which can be cultivated to a high pitch by “la grande habitude de voir”. There is nothing magical about this faculty; it is the subconscious result of long labour acting upon an instinctive interest.

In grasses the spikelets form the ultimate divisions of a type of branched raceme often vaguely described as a panicle. It is very difficult to define a grass panicle, but the features which give it its characteristic appearance are, firstly, the absence of axillant leaves, and, secondly, the abbreviation of the basal internodes of the branches, associated with precocious development of lateral axes; this second factor results in a confused crowding of branches of different orders. The lowest of the secondary branches may arise at the very base of the primary branch, and may, again, have a tertiary branch at its base, so that three branches, arising apparently as a triplet, may yet be, in reality, of three different orders. Owing to this precocious branching, the secondary and later axes may form a pseudo-half-whorl at each node, these half-whorls alternating along the primary axis. Examples of secondary and tertiary axes arising at the same node, and thus giving ‘twinning’ of branches of different orders, may be seen in Fig. 54, A1 and A2 (Briza media L.). The hair-like lateral axes, at the ends of which the spikelets dance in the slightest breeze, have earned for this grass such dialect names as Earthquakes and Doddering Jockies. In some Gramineae, for instance, the Fescues, the panicles are one-sided; for though the primary branches stand alternately to right and left, they do not lie in one plane, as one would expect of branches axillary to distichous leaves, but their planes meet at an angle which is less than 180°, so that they all stand out to one side of the axis.

In the preceding chapter, we considered the structure and anthesis of the reproductive shoot in grasses, omitting the more aberrant forms. Even when the field was thus limited, we met with a series of instances in which the divergence from the ‘typical’ Monocotyledonous floral diagram—or even from the more restricted scheme developed in the Bambuseae—followed the direction of fusion or suppression of parts. Examples which may be recalled are: fusion of the outer empty glumes; absence of the third lodicule; fusion of the remaining pair; absence of one whorl of stamens; loss of two of the three stamens of the remaining whorl; and the uniovular character of the gynaeceum. In this chapter we shall continue to study the subject of reduction, both in typical grasses and in the more peculiar examples in which the factor is specially apparent. It is remarkable that this reduction-trend—though itself, in the last analysis, a negative character—has led to an exceedingly varied series of forms.

Certain modifications in the outer empty glumes may first be discussed. The inflorescences of the curious little grass, Cornucopiae cucullatum L., have delicate cupules, each of which encloses one spikelet; they are drawn in Fig. 72, D and E, while the structure is shown in section in F–H. Unlike certain former writers, I interpret the cupule as consisting of the first and second outer empty glumes in a state of fusion.

It is a matter of common observation that no family of flowering plants includes so great a number of individuals as the Gramineae—a fact which seems in part accounted for by their extraordinarily prolific and effective seeding. There are a number of detailed records confirming this general impression. As long ago as 1660, Sir Kenelm Digby related that the “Fathers of the Christian Doctrine at Paris doe still keep by them for a Monument (and indeed it is an admirable one) a Plant of Barley consisting of 249. stalkes, Springing from one Root or Grain of Barley, in which they counted above 18000. Grains or seeds of Barley”. Later in the seventeenth century, Thomas Everard recorded that from one grain of Wheat he had obtained eighty ears and above 4000 grains. Seeding on this scale may lead to a rapidity of increase which seems almost miraculous. A few years ago the chief kind of Wheat grown in Canada was that known as ‘Marquis’. One grain of Marquis was planted in an experimental plot at Ottawa in the spring of 1903, and in 1918, from the progeny of this grain after fifteen years, 300,000,000 bushels of Wheat were produced in Canada and the United States.

In the grasses there is normally a period of seed-rest before germination. The whole subject of seed-rest, and the related problem of delayed germination, seem to need a thorough comparative study, for our present knowledge of these questions is only complete enough to reveal much obscurity.

Among the Gramineae, the distinction between the towering, woody bamboos, and the herbaceous grasses and cereals, is so striking that an effort of the mind is needed before we can think of them together, as members of a single and seemingly natural family. In Chapter iv we treated the tree habit of the bamboo merely as an observed fact; in this chapter we shall make an attempt to understand something of its significance. It cannot, however, be interpreted at all, if it is considered as an isolated phenomenon; in order to get any glimmering comprehension of it, we shall be obliged now to turn to the problem of the dendroid and herbaceous type in the flowering plants as a whole. From the earliest times at which a desire to pigeon-hole the facts of the world led man to attempt some kind of classification of the plants which he saw around him, the difference between the tree and the herb has seemed to him an important one. Theophrastus (born circa 370 .c.), the earliest scientific botanist of whose opinions we have a record, divided plants into the tree, the shrub, the undershrub and the herb. His classification thus makes a fundamental distinction between the arboreal and herbaceous habits, though his shrubs and undershrubs to a certain extent form a transition between the two.

The first point which strikes one about the mode of occurrence of the grasses on the face of the earth is their gregariousness. All meadows and many gardens in this country bear witness to the way in which the Gramineae, while living sociably among themselves, oust other plants. The same herd behaviour, coupled with exclusiveness, reappears among the bamboos. An American botanist, who has made a special study of the trees and shrubs of Japan, writes that in that country, “the forest-floor is covered, even high on the mountains, and in the extreme north, with a continuous, almost impenetrable, mass of dwarf Bamboos of several species, which makes traveling in the woods, except over long-beaten paths and up the beds of streams, practically impossible. These Bamboos which vary in height from three to six feet in different parts of the country…prevent the growth of nearly all other under-shrubs, except the most vigorous species”. The same writer attributes the climbing habit, which characterises so many Japanese plants, to this dense undergrowth of bamboos, which renders any other mode of life impracticable for relatively small species, if they are to keep a footing in the forests. The Gramineae are indeed formidable competitors in the struggle for space, not only because of their faculty for adopting a mass formation, but because they show an amazing tolerance about the external conditions of their lives.

In considering the arboreal habit, we noticed that the flowers of the Bambuseae were developed on a fuller plan than those of the other grasses, and approached more nearly to the complete Monocotyledonous type. This contrast will be realised on comparing Fig. 33, which represents the flower of a bamboo, with Fig. 34, p. 111, which shows the relatively reduced flower of Rye. It is thus obvious that the best way to understand the flower of the Gramineae is to start with the bamboo, but, unfortunately, the historical process has followed the reverse direction. Because analytical botany began in temperate regions, there has been a tendency to treat the exiguous European grass as the type form for the Gramineae. This has led to an exaggerated idea of the degree of peculiarity of the flower in this family, which has found expression in a special and elaborate terminology. Much of this terminology, and also of the controversy which has raged about the interpretation of the ‘palea’ and “lodicules’, might have been spared, if the study of the Gramineae had proceeded from the tropics to the temperate regions, and not vice versa. So, in order to follow the logical course, we will now examine the flowers of the bamboos, leaving those of the ‘grasses’, in the limited sense, to be dealt with in later chapters.

In the bamboos which flower annually, the inflorescence terminates the leaf-bearing culm; but in those which are gregarious and periodic flowerers, the leaves fall, and the whole culm becomes one huge reproductive shoot.