Ligule. 
Spikelet. 
Glumes. 
Lower Pale. 
Upper Pale. 
Inflorescence. 
The arrangement of the leaves in the bud — the prefoliation or vernation — is of great impor- 
tance in distinguishing grasses. In the bud, the blade is either folded (conduplicate, Pl. Ill, Fig. 11) 
or rolled (convolute, Pl. II, Fig. 10). The arrangement is determined, either by direct examination of 
the young leaves, or from a transverse section. The folded arrangement is much rarer its than the 
other: among fodder grasses, Crested dogstail, Cocksfoot, Sheep’s fescue, Perennial Ryegrass, and Poas, 
have alone folded leaves. 
The ligule is an outgrowth from the surface of the leaf, at the union of the sheath and blade. If 
is a thin transparent membrane; so to speak, a prolongation of the inner epidermis of the leaf-sheath 
(See Pl. I, Fig. ID. The characters derived fom it are often very important in distinguishing species. 
The flowers of grasses always form spikelets; the structure is shewn in Pl. IV Fig, 1. The awis 
of the spikelet bears two rows of alternate bracts. The lowest pair develop no flowers in their axils 
and are called glumes.*) Each of the other bracts which produces a flower in its axil is a lower pale.**) 
A bract of peculiar structure springs from the very minute flower-stalk, from that side of it which lies 
next the axis of the spikelet, this is the upper pale. 
The g/umes are placed very close together on opposite sides of the axis of the spikelet, but never 
exactly at the same level. They are known as lower and upper. The margins of the lower overlap 
those of the upper, and the lower is usually the smaller; at times, both are equal in size, and the 
margins do not overlap (See Timothy Pl. VII Fig. 1, and Foxtail Pl. IX Fig. 4). 
The first pale lies directly above the lower glume, the second above the upper glumes, and so on. 
The lower pale has often a strong midrib, called the keel or carina, when there is a strong fold along 
the midrib, so that the halves of the bract form an acute angle like the keel of a boat. There is al 
times a free prolongation of the midrib; this is the awn. The point at which the awn becomes free 
from the pale varies: it may spring either from the apex (terminal or apical awn, e.g. Italian Ryegrass 
Pl. Il, Fig. %) or from the middle of the back (dorsal awn, e.g. Golden Oatgrass Pl. VI, Fig. 4) or 
from the base (basal awn). Rarely, the glumes have awns e.g. Timothy (Pl. VII, Fig. 1) with short 
awns on the glumes, and Sweet vernal grass (Pl. X, Fig. 6) with long awns on the inner glumes but 
none on the outer. 
The upper pale has a somewhat different structure. Its margins are overlapped by those of the 
lower pale. It is not attached to the axis of the spikelet, but to the very short flower-stalk which 
stands in the axil of the lower pale. It is usually a delicate membrane and instead of a midrib, has a 
pair of lateral ribs ; these are placed near the margins and project as keels or carinae, hence this pale 
is described as bicarinate (See Pl. V, Fig. 3). 
The number of flowers contained in a spikelet varies much in different grasses. Timothy, Meadow 
foxtail, Sweet vernal, and Fiorin, have one-flowered spikelets (PI. VI, IX, X, XI); False Oatgrass and 
Yorkshire Fog, two-flowered spikelets (Pl. V, VII); Ryegrasses, Cocksfoot, Fescues etc., many-flowered 
spikelets. The number of flowers is readily determined by counting the lower pales, each of which 
corresponds to a flower. 
Frequently the glumes are longer than the pales, and in that case, the latter are concealed, ¢@. 4. 
Golden Oatgrass, Yorkshire Fog, Timothy, Meadow foxtail, Sweet vernal, Fiorin (Pl. VI—XI). In other 
cases the pales project considerably beyond the glumes e. g. Ryegrasses, Cocksfoot, Fescues (Pl. I—Y). 
Before considering the flower itself, let us glance at the various arrangements of the spikelets 
which form the inflorescences known as panicles and spikes. When the culm produces branches which 
bear spikelets, the inflorescence is a panicle+): when the culm does not branch, and the spikelets are 
directly attached to a simple axis, the inflorescence is a spike ++). 
*) Barren pales (Hackel). 
**) Fertile pale (Hackel). 
+) Strictly speaking a panicle of spikes. 
+i) Strictly speaking a compound spike. 
