23 © INTRODUCTORY ESSAY. 
.ss Im the: male spikelets .the partial inflorescences are usually branched two or 
three times and the division or branchlets which remain in their basal portions may 
be considered to be compound or branched spikes, while the ultimate divisions of 
these are the true or simple spikelets. 
As regards size, the different divisions of the inflorescence and the spikelets follow 
the general rule; the upper branches and spikelets are gradually smaller than the 
lower ones and every partial inflorescence assumes a more or less pyramidal form, 
The terminal spikelet of each division is usually considerably larger than the others. 
The male spikelets are almost always shorter and more densely furnished with 
flowers than the female ones. 
The axis of the male spikelets is clothed with spathels which are commonly 
broadly and asymmetrically infundibuliform (Prate I, fig. 14, and Prate II, fig. 4h); 
sometimes, however, their tubular part is so short that they look like bracts or are 
boat-shaped or spoon-shaped with the axis passing excentrically through them; the 
spathels are rounded on one side and slightly prolonged on the other, the outer, into 
a small point. 
In the axil of each spathel is a flower with its special involucre (PrarE I, 
fig. 1b, and Prare II, fig. 44). The involucre has usually the form of a small cup 
(Pate I, figs. 1-36), being more or less concave; in a few instances we find in 
place of the involucre two small scales or bracteoles united by their bases which clearly 
explain the origin of the involucre from two coalescing appendicular organs; for 
example in C., asperrimus, C. siphonospathus and cthers. 
Authors usually term the involucre a “‘spathellula,” a name that may easily be 
mistaken for that of a ''spathella," and -one that, as we shall presently see, has not 
been always properly and uniformly applied. In the simple spikelets it is always easy 
to, distinguish the spathels from the other appendicular organs as it is from the axils 
of these spathels that the flowers arise; but in the case of compound or branched 
spikes it is a spikelet, which has its own spathels, that is situated in the axils of a 
spathel; in this case therefore we have primary, secondary, and even tertiary spathels, 
according to the degree of division of the primary spike. But all this is of very 
slight importance since, as a rule, the secondary and tertiary spathels differ from the 
primary only in size. It is sufficient if we hold that in a male spikelet we mean 
by a spathel the appendicular organ which clothes the axis of a spikelet—whether of 
& primary or a secondary spikelet is of no consequence—and that a spathel of the 
ultimate bridge eoe: a culis which in turn has its base enveloped by a special 
involucre. 
The modifieations, peculiarities and diagnostie characters afforded by the spathels 
are essentially the same as those of the female spathels to be described further on; 
but as a rule the spathels of the male spikelets are shorter, broader, more distinetly 
infundibuliform and more closely packed than those of the other sex. The flowers of 
the male spikelets are solitary in the axil of each spathel except in a very few 
species; such as O. viminalis, C. pseudo-tenuis and some few others. In @, viminalis I 
have counted as many as 8 glomerulate flowers to each spathel; but in this case 
the glomerules must be considered secondary much reduced diss as. odi flower 
is provided with its own diminutive bracteole. 3 E. um 
