404 GRAMINE*. 



thin, adhering to the seed or rarely loose or opening in 2 valves. Embryo 

 small, at the base of a mealy albumen. — Herbs, with stems usually hollow ex- 

 cept at the nodes, sometimes shrubby or arborescent in their stature and hard- 

 ness of the stem, but very unUke dicotyledonous trees or shrubs. Leaves alter- 

 nate, entire, paraEel-veined (usually long and narrow), sheathing the stem at 

 their base, but the sheaths split open on the side opposite the blade, and often 

 end within the base of the blade in a scarious appendage called a ligula. 

 Spikelets aiTanged in terminal spikes, racemes, or panicles. 



A very large Order, abundantly diffused over the whole world, and supplying many of the 

 most important articles of food and raiment, or applied to a great variety of economical pur- 

 poses. The terminology here used in describing the spikelets is in conformity with the views 

 of Mohl and others, which appear to me to be at oilce more plausible in theoiy, and practi- 

 cally more in conformity with appearances than that more generally adopted, in which the 

 flowering glume and palea are both considered as floral envelopes under the name of lower 

 and vj^er paleas. Under this view aU empty glimies except the 2 lowest (or sometimes one 

 of the two lowest, even when these are exactly alike) are called sterile florets, the naine glume 

 being reserved exclusively for the one or two lowest. 



A. Spikelets 1-flowered, i. e. with one fertile flower, with or without a second male one 

 below it, or 1 or more additional empty glumes besides the outer ones. (See also B, S.) 



1. Spikelets sessile or shortly pedicellate, forming a dense cylindrical spike, raceme, or 



Howering glumes awned. 



Spikelets flat. Awn very slender and short, on the back 



of the glume 1. Alopbcueds. 



Spikelets convex, in pairs, surrounded by long hairs. Awn 



terminal, twisted at the base ..•,,.... 22. Pogonatherum. 

 Outer glumes awned. 



Bacemes simple. Awns much longer than the glumes . 15. Peeotis. 

 Panicle branched but dense and spike-like. Awns very 



short. 31. PoLYPOGON. 



Glumes all awnless. 



Spikelets surrounded by long awn-like bristles. 



Panicle branched though dense and spike-like, the bris- 

 tles irregularly intermixed 4. Panicum (a. 8). 



Baceme or spike long and simple, the bristles forming 



an involucre round the spikelets ...... 5. Gymnothkix. 



Spikelets enveloped in long silky hairs 18. Impebata. 



Spikelets without bristles or long hairs. 



Outer glumes 3 ; flowering glume hard 4. Panicum (n. 17). 



Outer glume 1; flowering glume very thin . . . .16. Zoysia. 



2. Spihes singly sessile or in pairs, in 3 or rarely 4 rows, in a simple usually 1-sided 

 spike, or in the sessile spike-like branches of a simple panicle. 

 Spikelets awnless or with straight awns. 

 Spikelets hermaphrodite. 



Flowering glume enclosing the grain, as stiff as or 

 harder than the outer ones. 

 Glumes concave, 3-nerved. Fertile flowers terminal. 

 Two outer empty glumes besides the flowering one 2. Paspalum. 

 Three outer glumes all empty^or the third with a 

 male flower, the lowest often very minute . . 4. Panicum (n. 1 to 7). 

 Glumes strongly keeled. Axis of the spikelet pro- 

 jecting beyond the palea. 

 Axis ending in a minute point at the back of the 

 palea . 86. Cynodon. 



