Mode 
of Growth. 
Perennial grasses have, like annuals, a main stem with branches springing from its base; but, 
unlike the annuals, the branches do not flower in the same season as the main stem. They remain sterile 
in winter, and during next season produce flower and fruit, like the main stem. Before they die, a new 
brood of branches, destined to continue the growth during the next period of vegetation, is produced. 
2 2 Fig. 2 is a diagrammatic representation of a 
perennial grass, as it would appear, say in the summer 
of 1886. The persisting remnant of the culm from 
the preceding year is marked 4. The culm marked 
2 is a basal and lateral outgrowth from culm 4, In 
1885 it was present as a leafy shoot, but now (in 1886) 
it has lengthened out, and reached the flowering 
stage. From its base, the leafy barren shoot mar- 
ked 3 has been produced. This shoot will reach 
the flowering stage in 1887. At the base of 3, a 
lateral bud is seen; it will unfold, and form a tuft 
of leaves (like 3), in 1887, and reach the flowering 
stage, in 1888. The presence of barren shoots, such 
as 3, is a certain sign of a perennial grass*). Moving 
interferes with this typical mode of development, 
and causes some of the lateral shoots to develop like those of annual grasses. In Diagram 2, one shoot 
is represented as originating from the base of the culm, whereas, in reality, numerous shoots are pro- 
duced. The amount of produce depends upon the number of such lateral shoots. 
In perennial grasses the underground parts (Fig. 2) persist for lengthened periods; they form the 
rhizome or root - stock, Instead of ordinary foliage, these underground stems are provided with brown 
or colourless scales (Fig. 2), and the nodes are not swollen. Above ground, the dried up bases of old 
culms (1, Fig. 2) also persist; they, like the rhizome and the barren shoots, mark the grass as perennial. 
According to the mode of growth, perennial grasses may be divided into two groups: — 
1. the tufted or cwspitose, and 2. the creeping or stoloniferous. This grouping depends upon the 
length of the underground parts of the branches i. e. of the parts which make up the rhizome. The 
branches may ascend directly above ground as in Fig. 1; the underground parts are then very short, 
and the aerial parts stand close together forming tufted grass. On the other hand, the branches may, 
as in Fig. 2, run for a distance horizontally beneath or on the surface of the ground; the aerial 
parts of such a system of branches stand widely separate, forming creeping grass. The horizontal portion 
of the branch is often spoken of as a sfolon, and the growth as stoloniferous. Between these extreme 
modes of growth, all gradations are possible. The following terms may be applied, — closely tufted, 
loosely tufted, slightly creeping, widely creeping. 
The mode of growth of tufted grasses may be further defined by the behaviour of the lateral 
branches. As already indicated, the branches always originate in the axils of the lower or radical 
leaves. Such a branch grows up, either within the leaf-sheath (intravaginal branch), or it bores its way 
through the base of the sheath which encloses it, and grows up outside of the sheath (extravaginal 
branch). 
In the case of creeping or stoloniferous grasses, there must always be extravaginal branches. On 
the living plant it is very easy to distinguish the extravaginal and intravaginal. When they break 
through the sheath and are extravaginal, the base of the culm shows a number of small, white, conical, 
*) These cannot be confounded with the young shoots of annual grasses. In such, when the leaves are pulled 
asunder, the young inflorescence, which they surround and conceal, is seen. 
