SOME COLORADO GRASSES. 
7 
into a matted turf. Its function is the appropriation of 
food from the soil, to be conveyed to the stem and leaves. 
The stem is technically called a culm, because hollow 
between the joints. It is divided, at intervals, by thick¬ 
ened portions called nodes, which give it additional 
strength. The stem is sometimes horizontal and subter¬ 
ranean, when it is botanically known as a rhizoma. In a 
few cases the stem exhibits a bulbous enlargement at its 
base, in which is stored nutriment for the plant’s use 
under adverse circumstances. 
The leaves are in two vertical ranks, parallel veined, 
the lower portion of the leaf sheathing the stem, but with 
the edges free. The expanded portion above is the blade. 
It is either filiform, linear or lanceolate. 
At the junction of the sheath and blade is a short 
membrane, called the ligule or tongue, answering to 
stipules in the higher plants. 
The inflorescence may be in the form of a spike, 
more or less dense or more spreading, as in the receme, or 
still more branching, as in the panicle. It is sometimes 
of importance to note whether these branches are in Is, 
2s, 3s or 5s. 
The flowers are collected in little clusters called 
spikelets. One of the latter, separated into all its parts, 
would be found to consist of two scales at the base, stand¬ 
ing opposite each other, of equal or unequal length, 
called the outer glumes, and one or more such is a 
spikelet. 
The flower consists of two scales standing opposite 
each other. The largest is called the flowering glume, 
and is of a coarser texture than the smaller, called the palet. 
Between these two scales there are usually three 
stamens, with delicate filaments and versatile anthers, and 
the pistil, with its two feathery stigmas. 
