GRAMINE^. (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. POACE^, R. Br. Bpikelets 1 - many-flowered, when more than one-flowered 

 centripetal in development 5 the lowest flowers first developing, uppermost, if any. imper- 

 fect or abortive, the rest all alike in the Bpikelet (perfect, or occasionally monoecious or dioe- 

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

 than the upper (viz. stamioate only in Arrhenatherum and Phragiuites, neutral in Uniolu, 

 Ctenium, &c.). 



Subtrlbe 1. Oryzece. Splkelets 1-floWered, in patiicles, th6 flowers often monoecious. 

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



1. Leersla. Flowers perfect, strongly flattened contrary to the awnlesa condUplicate palets. 



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



Subtribe 3. Agrostidete. 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 oh the 

 common axis. Stamens 1-3. 



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



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



8. Alopecurus. Glumes united at the base. Lower palet bearing an awn on the back : 



the upper palet wanting. 



4. Plileiim. 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. 



* # AGROSTIDEiE 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 sotae very minute ones at the base. 



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



6. Vilfa. Fruit a caryopsis (seed adherent to the pericarp, as in most gi-asses). t^anlcle 



spiked or contracted. 



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

 •*- -- Flower slightly iraised 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. Ag^rostls. 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. PolypoKon. 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. Ciniia. 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. Muhlenber^ia. Lower glume mostly smaller Palets chiefly bairy-bearded at the 



base, the tip of the lower one mucrouate-poioTed or awned. Stamens 3. 



12. Bracliyely trnm. 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 

 haked pedicel of an abortive second flower. Stamens 2. 



* * « CAL.\MAGROSTIDE^. 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, shorterthan the glomes. 



