CLASS IV. ORDEE L 



37 



nhorter than the florets, with one large 

 glume, keeled, pointed ; corolla with the 

 lower valve keeled, eniarginate, mucro- 

 na.te, upper valve sub-couduplicate. (or- 

 chard-grass.) 



K(Kle'ria. Glume 2 to 4-flowered,8hort- 

 er than the florets ; lower palea mucronate, 

 or with a short bristle a litde below the tip. 



Fkstu'ca. Spikelets oblong, more or less 

 terete, at length compressed, acute at each 

 end ; florets sub-terete ; glumes unequal, 

 shorter than the lower florets, keeled, 

 acute ; paleas lanceolate, the lower one 

 acuminate or rounded at the extremity, 

 (fescue-grass.) 



Bro'mus. G-lumes 2, shorter than the flo- 

 rets ; spikelets terete, 2-ranked, many-flow- 

 ered ; outer paleas bifid, awned below the 

 tip, inner one pectinate-ciliate, sub-condu- 

 plicate. (chess, broom-grass.) 



Dantho'nia. Glumes 2 to 5-flowered, 

 longer than the florets, cuspidate ; palea, 

 bearded at the base, lower one 2toothed, 

 with a twisted awn between the teeth, 

 upper one obtuse, entire ; panicle spiked, 

 (wild-oats.) 



Ai'ra. Glumes 2, rarely 3-flowered, 

 beardless, 2-valved, equal to the florets, or 

 shorter; one of the florets peduncled ; pa- 

 leas 2, equal, enclosing the seed when 

 ripe, outer one usually awned ; panicle 

 compound. 



Ave'na. Calyx 2-valved ; 2, 3, or many- 

 flowered ; corolla with valves mostly 

 bearded at the base, lower one torn, with 

 a tw^isted aw^n on the back ; glumes mem- 

 branaceous, and somewhat follicle-like; 

 seed coated, (oats.) Ex. 



[Flowers in spikes.'\ 



Lo'lium. Calyx 1-leafed, permanent, 

 many-flowered ; florets in many-flowered, 

 2-rowed, simple, sessile spikelets on a ra- 

 chis, loAver valve of the corolla herba- 

 ceous-membranaceous, mucronate, or bris- 

 tled at the tip. (darnel-grass.) 



Trit"icum. Calyx 2-valved, about 3- 

 flowered ; florets sessile on the teeth of the 

 rachis, obtusi.sh and pointed ; glumes beard- 

 less, or interruptedly bearded, (wheat.) 

 Ex. 



Sesle'ria. Glumes 2 to 5-flowered; pa- 

 leas 2 ; stigmas sub-glandular; base of the 

 spike bracted or involucred. (moor-gi-ass.) 

 6'. 



Meli'ca. Glumes unequal, 2 to 5-flower- 

 ed, membranaceous, nearly as long as the 

 florets, of which the upper are incomplete 

 and abortive ; scales truncate, fimbriate ; 

 seed loo.se, not furrow^ed ; panicle simple 

 or compound, (melic-grass.) 



Seca'f.e. Calyx 2-valved, 2 or 3-flowered ; 

 spikelets sessile on the teeth of the rachis, 

 with the tenninal floret abortive ; calyx 2- 

 valved ; glumes subulate, opposite, shorter 

 than the florets; corolla with the lower 

 valve long awned. (rye.) Ex. 



D. Fhu-crs polygamous. {In panicles.] 



Pan''icum. Calyx 2-valved, 2-flowered ; 



the lower glume generaUy very small ; the 



lower floret abortive, 1 or 2-valved , the 

 lower valve resembling the calyx, the up- 

 per one membraiiaccuus ; perfect floret 

 with cartilaginous valves, unarmed, (cock- 

 foot gra.-^s, panic-grass.) 



Hol"cl's. Glumes 2-valved, 2-flowered, 

 nearly equal ; paleas 2 ; florets dis.similar, 

 polygamous, one awned, the other awnlcss, 

 without any imperfect one between them; 

 panicles contracted. • 



[In spikes.] 



Hor^'deum. Spikelets 3 at each joint of 

 the rachis, 1 or 2-flo\vcred, all perfect, or the 

 lateral ones abortive ; glume lateral, subu- 

 late ; perfect flow^er with a 2-valved corol- 

 la, lower valve ending in a bristle ; seed 

 coated, (barley.) Ex. 



Androp"ogon. Spikelets in pairs, invo- 

 lucred, the lower one staminate or neutral, 

 on a bearded pedicel ; glumes and palea.9 

 often veiy minute, or \vanting ; upper spiko 

 lets sessile, 1-flowered, perfect ; glumes sub- 

 coriaceous ; paleas 2, shorter than the glumes, 

 membranaceous, lower valve generally awn- 

 ed. (beard-grass.) 



Pennise'tum. Inflorescence, a compound 

 cylindrical spike ; spikelets 2-flowered, in- 

 vested w^ith an involucrum of 2 or more 

 bristles ; glumes 2, unequal, herbaceous ; 

 superior florets perfect ; paleas cartilaginous, 

 (bristled panic.) 



Rotbol''lia. Rachis jointed, somewhat 

 terete, often filiform ; calyx ovate-lanceo- 

 late, flat, 1 or 2-valved, 1 or 2-flowered ; flo- 

 rets alternate on a flexuous rachis. S. 



Monoce'ra. Flowers in 2 rows on one 

 side of the rachis ; glumes 3, many -flowered, 

 valves a\viied below the tip. Peifect flow- 

 ers have 2 paleas, unequal, outer valve 

 awned below the tip. Neutral flowers have 

 2 awnless paleas. S. v 



order III. trigynia. 



Mollu'go. Calyx 5-leaved, colored with- 

 in ; corolla ; capsule 3-celled, 3-valved. 

 (cai-pet-weed.) 



Leche'a. Calyx 3-sepalled ; petals 3, 

 linear; stigmas 3, plumose ; capsule 3-ccUed, 

 3-valved, with 3 inner valvelets ; seed 1. 



Mon"tia. Calyx 2 to 3-sepalled ; petals 5, 

 sub -connate at the base, 3 rather small ; sta- 

 mens on the claNvs of the petals, mostly be- 

 fore the 3 smallest ; styles short, reflcxed ; 

 capsules 1-celled, 3-valved, 3-seeded. 



Polycar'^pon. Calj-x 5-sepalled ; petals 

 5, very short, emarginate, permanent ; cap- 

 sule ovate, 1-celled, 3-valved. iS. 



Proserpina'ca. Calyx 3-parted, superi- 

 or ; coroUa ; fruit a hard nut, 3 -sided, 3- 

 seeded, crowned by the caljTC. (mennaid- 

 weed.) 



CLASS IV. TETRANDRIA. 



ORDER I. MONOGY.VIA. 



A. Flowers superior, [l-pclalled.] 

 Allio'nia. Common calyx oblong, sim- 

 ple, 3 -flowered, proper calyx obsolete ; co- 

 rolla irrci^ular ; receptacle nakt;d. 



Cephalan"tkus. Inflorc-fconce in a 

 head ; general calyx none, f roper calv>j 



