LXXX1IX, GRAMINEA. 503 
proceeding from the point of the glume or from a notch at the top, or is 
inserted lower down, on its back, or at its very base. Sometimes the whole 
spikelet contains only two glumes, one empty, the other flowering, with or 
even without a palea, or is reduced to a single flowering glume and palea, 
and in a very few 1-flowered spikelets. it may be doubtful whether the 
2 inner scales should be considered as-a glume and a palea, or as 2 glumes 
without any palea. Many botanists restrict the name of glume to the outer 
empty pair, calling both the flowering glumes and their palea, paleas or 
glumellas, and giving the name of sterile florets to all other empty glumes 
in the spikelet, or even to a small prolongation of the axis which is often 
observable at the outer base of the palea of the terminal flowers. The 
leaves of some Girasses are described as convolute, that is, rolled inwards on 
the edges, but the character is often very deceptive in dry specimens, for 
in many species the leaves are perfectly flat when growing, but roll inwards 
in drying immediately on being gathered. 
Grasses are abundantly diffused over the whole world, from the utmost 
limits of phenogamous vegetation towards the Poles or on alpine summits, 
to the burning plains of the Equator. In temperate regions they form the 
principal mass of the green carpeting of the soil, whilst in tropical regions 
some species (the Bamboos) attain the height of tall trees. They supply 
us with one of the most important articles of food for man, in the shape of 
grain, and for cattle as constituting the chief portion of meadows and 
pastures. 
1 { Spikelets 1-flowered ‘ ‘ 5 : } 5 ‘. - Pe da 
Spikelets containing 2 or more flowers. : . . 24 
Spikelets arranged along one side of-a slender, simple, css ‘spike ; Sk: 
Spikelets arranged along one side of the simple, linear branches of thepanicle 5 
Spikelets arranged in a close, cylindrical or ovate spike or spike-like panicle 7 
Spikelets arranged in a loose, branching panicle . . . . ° 16 
2 
Spikelets l-flowered, in one-sided near spikes, 
Glume 1 only, ending i in a fine point, and enclosing the palea and flower. 
3 24, NARDUS. 
Two outer empty glumesand a flowering one . 4 
Onter glumes 1 line long, thin, and obtuse. Axis not jointed 10. CHAMAGROSTIS. 
4 < Outer glumes 2 lines long, stiff, and strongly ribbed. Axis jointed. 
; 23. LEPTURUS. 
5 { Spikelets in pairs or clusters along the branches 1 . 3. PANIC ber 
Spikelets single along the branches . 
Spikelets haif an ‘inch long, laterally flattened. Glumes all ‘strongly ediban 
of erect ; : . 22, SPARTINA, 
Spikelets about a line long. Outer glumes spreading : . 21, CyNopDON. 
Spikelets 1-flowered, in a dense spike or spike-like panicle. 
7 f Outer glumes without awns. Flowering glumes with or without awns. 3 
Allithe glumesawned . . : . : od 
Only 2 nearly equal empty glumes enclosing the flower . ; ; ° ~ 9 
An additional small empty glume outside the 2equalones . 3. PANICUM, 
. Two additional small, awned, empty glumes, withinside the two equal ones. 
5. ANTHOXANTHUM, 
Outer glumes swollen and shining at the base. Spikelets rather small. 
. 14, GASTRIDIUM. 
Outer glumes keeled or boat-shaped . ; . 10 
A tuft of hairs at the base of the flower, within the outer elume. Reed-like 
10 grass with avery long spike . : 15. PSAMMA. 
No tuft of hairs outside the flower within the outer glumes. Spikelets flat . 11 
Flowering glume with a fine awn on its back (sometimes shorter than the outer 
nf glume). Noinnerpalea . : : - 9, ALOPECURUS. 
Flowering glumes without awns. Inner palea present SLi Sipent hal ept ieee Ce 
