GRAMINE^E. (GRASS FAMILY.) 603 



sometimes permanently adherent to, the palets. — A vast and most impor- 

 tant family, as it furnishes the cereal grains, and the principal food of cat- 

 tle, &c. (See Plates 7-14.) 



Tribe I. POACEiE. R.Br. Spikelets 1 -many-flowered, when more than one-flowered 

 centripetal in development ; the lowest flowers first developing, uppermost, if auy. imper- 

 fect or abortive, the rest all alike iu the spikelet (perfect, or occasionally monoecious or dioe- 

 cious) ; only in a few exceptional cases with the lowest of the several flowers less perfect 

 than the upper (viz. staminate only in Arrhenatherum and Phragmites, neutral in Uniola, 

 Ctenium, &c). 



Sub tribe 1. Oryzeae. Spikelets 1-flowered, in panicles, the flowers often monoecious. 

 Glumes abortive or wanting! Inner paleae 3-nerved! Stamens 1-6. 



1. Lcersia. Flowers perfect, strongly flattened contrary to the awnless conduplicate palets. 



2. Zizania. Flowers monoecious. Palets convex ; the lower one awned in the fertile flowers. 



Subtribe 2. Agrostitlr se. Spikelets 1-flowered, perfect, and occasionally with the 

 rudiment or abortive pedicel of a second flower above, panicled, or clustered, sometimes so 

 contracted as to form a sort of spike, but the spikelets are not directly borne on the 

 common axis. Stamens 1-3. 



* PIILEOIDEJE. Glumes equal, strongly keeled, laterally flattened, boat-shaped, somewhat 



herbaceous, as well as the palese. Inflorescence densely spiked ! 



3. Alopeeurus. Glumes united at the base. Lower palet bearing an awn on the back: 



the upper palet wanting. 

 i. Phleisiin. Glumes distinct, sharp-pointed, much larger than the two thin and truncate 

 awnless palets 



5. Crypsis. Glumes distinct, not longer than the palets ; both awnless and pointless. 



* * AGR.0STIDEJE proper. Glumes and palets both membranaceous, or the latter sometimes 



very thin and delicate. Inflorescence panicled or glomerate, sometimes rather spike-like, 

 but not contracted into a uniform cylindrical spike. Palets not surrounded by a tuft of 

 hairs, or only with some very minute ones at the base. 



-i- Flower perfectly sessile in the glumes : lower palet 1-nerved : awns none. 



6. Vilfa. Fruit a caryopsis (seed adherent to the pericarp, as in most grasses). Panicle 



spiked or contracted. 



7. Sporobolus. Fruit an utricle (seed loose in the thin pericarp). Panicle open or close. 

 +- h- Flower slightly raised in the glumes on a short sometimes stalk-like base (callus) : lower 



palet 3 -5-nerved ; and this or the glumes awned or pointed, except in some species of No. 8. 

 8- Agrostis. Glumes equal, or the lower one rather longer, pointless, exceeding the very 

 thin blunt palets. Lower palet pointless, often awned on the back ; the upper sometimes 

 wanting. Panicle open. 

 9. Poly pogon. Glumes nearly equal, long-awned, much longer than the palets, the lower 

 of which is often short-awned below the apex. Stamens 3. Panicle contracted. 

 10. Cinna. Glumes acute, the lower about equalling and the upper slightly exceeding the 

 similar palets. Stamen 1. Flowers raised on a distinct naked stalk, beardless : lower 

 palet short-awned or bristle-pointed just below the tip ; the upper 1-nerved. 

 11 Mublenbergia. Lower glume mostly smaller. Palets chiefly hairy-bearded at the 

 base, the tip of the lower one mucronate-poinied or awned. Stamens 3. 



12. Brachyelytrum. Lower glume almost obsolete, and the upper minute. Lower palet 



long-awned from the tip ; the upper grooved on the back and bearing a long and slender 

 naked pedicel of an abortive second flower. Stamens 2. 



* * * CALAM AGROSTIDE,E. Flower with a copious tuft of hairs at the base of the palets : 



otherwise as in the foregoing subdivision. 



13. Calamagrostis. Lower palet mostly awned on the back, shorter than the glumes. 



