594 



CLXI. GRAMINE^l. 



Conspectus of the Genera. 



fl-fruited, . . (in spikes, 



( in panicles, 

 Spikelets 12 OO-fruited, ( in spikes. 



< with awns. . l 

 in panicles, fc without awns. 2 

 ' with awns. . 3 

 without awns. 4 

 with awns. . 5 

 without awns. 6 



7 



$ Fr. white. Oryzopsis. 

 $ sessile. ( Fr. black. Piptatherum. 

 ("cartilaginous, (stipitate. Fr. black Stipa. 

 ' naked. Stam. 1. Cinna. 

 hairy. Stam. 3. Calamagrostis. 

 Agrostis. 

 Aristida. 



} herbaceous, . 



s with lawn, Imembranaceous, 1-keeled. 

 Pales 2, (. the lower with 3 awns, often twisted. 



( Glumes t 1-flowered. \ Pales 3, upper one with an awn. Flowers polygamous. Sorghum. 

 I large, (2-flowered (one flower abortive), longer than the paleae. . . . Holcus. 



\ { unequal, one of them hardly perceptible Muhlenbergia. 



Glumes minute, (subequal, one of them awned Tricliochloa. 



Si. I Glumes 0. Aquatic grasses Zizania. 



\ Fr. coated. Agrostis. 

 $ Stig. 2. { Fr. naked. Sporobolus. 

 $ membran'ous. ( Stigmas 3. . . Psamma. 



\ Paleae 2, ( coriaceous Milium. 



Glumes 2. (Paleae 1. Panicle mostly capillary. . . Trichodium. 



{ Spikelets 1-flowered. 

 1 Spikelets 2-flowered. 



Glumes 0. Leaves retrorsely scabrous. 



Leersic 



Glumes 2, very unequal, resembling the outer abortive pales. Panicum. 



Glumes 2, equal, longer than the pales. . . . Phalaris. 



2. L Spikelets 3-flowered, 2 of the flowers staminate, the other perfect. . . . Hierochloa. 



$ Pal. with awns 13 times their length. Alopecurus. 

 ( Involucre 0. ( Pales with awns 5 times their length. Hordeum. 

 < Spikelets with an invojucre of 2 or more bristles. Setaria. 

 ( subsimple. ( Spikelets with a burr-like involucre. . . . Cenchrtis. 



\ Both glumes and pales awned. . . Polypogon. 



i Spike solitary, ( paniculate or lobed. (Glumes awnless, pales awned. . . Anthoxanthum. 

 < Spikes 00, not bearded, unilateral, panicled. Pales cartilaginous. . . . Oplis'/nenus. 

 3. ( Spikes 200, polygamous. Sterile flowers plumosely bearded. . . . Andropogon. 



( solitary, terminal. . . . Phleum. 



(Spikes cylindrical, ( several, terminal and lateral. Crypsis. 

 fl 00; spikelets suborbicular. Paspalum. 

 ! digitate or verticillate, linear. Disritaria. 

 I pedunculate in a 2-sided panicle. Bpartina. 

 CFls. perfect or polygamous. L Spikes unilateral, L sessile in a unilateral panicle. Lepturus. 



\ all terminal, stenle above, fertile at base. . . Tripsacum. 

 4. ( Spikes monoecious, . . { fertile ones lateral, sterile ones terminal, panicled. Zea. 



$ Apex bifid. Awn bent. . 

 (" near the base. (Apex multifid. 



( which has two bristly teeth 

 < which is merely bifid. 



f Lower palea awned on the back I near the apex ( which is entire. . 

 f which is entire. Fruit coated. 



j < with a cusp each side of it 



5. I Lower palea awned at the apex ( between the two teeth : awn twisted. 

 Pales entire, not mucronate, bristly at base. . 

 Pales bidentate, outer one mucronate. . 



Pales entire, outer one mucronate 



Pales cartilaginous, outer cuspidate, coating rruit. 



Outer palea bifid and tricuspidate 



Outer palea erose-denticulate. Spikelets terete. . 

 Pales not mucronate, inner one bifid. 



Outer palea truncate-mucronate, inner bifid. . 



I perfect. . . ' Spikelets cordate at base, tumid, pendulous. .... 

 I Panicle contracted. 



6. (.Terminal flower abortive or a mere pedicel. ( Panicle large, diffuse. 



$ one (in the top spikelet 2). . 



( Glumes broad, . . ( two in each spikelet 



C collateral : spikelets in 2s, &c. 

 ("Spikes 2-ranked, ( Glumes subulate, (opposite : spikelets solitary. 



( Spikelets 

 f Terminal fl. < not cordate. 



4 Spikelets in two rows, 

 r Spikelets in one row. . 



Avena. 



Aira. 



Trisetum. 



~Bromus. 



Gymnopogon. 



Festuca. 



Uralepis. 



Danthania. 



Arundo. 



Ceratochloa. 



Festuca. 



Diarrhena. 



Tricuspis. 



Glyceria. 



Poa. 



Uniola. 



Sriza. 



Koeleria. 



Melica. 



Lolium. 



Triticwm. 



Elymus. 



Secaie. 



Eleusine. 



Cynodon. 



Atheropogon. 



Dactylis. 



< ( digitate (rarely solitary) 



^ remote, short, forming a long, slender raceme. 

 7. L Spikes unilateral, ( conglomerate or paniculate 



FIG. 56. 1. Agrostis alba ; a 1-flowered spikelet ; a, the two glumes. 2. A flower, with the two paleae, 

 three stamens and two plumose stigmas. 3. Leersia oryzqides ; a flower removed from its glumes, 

 showing its 2 hypogynous scales, three stamens and ovary with the two stigmas. 4. Phleum pratense ; 

 a l-flowered spikelet; a, glumes; b, truncate pales ; &c. 5. Polypogon; a 1-flowered spikelet ; glumes 

 and lower palea awned. 6. Holcus lanatus; a two-flowered spikelet; a, glumes; b, the two flowers 

 (upper staminate). 7. Poa pratensis ; a 4-flowered spikelet ; a, the two glumes ; 6, a single flower, with 

 two pales, &c. 8. Festuca duriuscula ; a 5-flowered spikelet : a, two glumes ; ft, a single flower. 9. The 

 caryopsis of Hordeum, showing the embryo at the base of the copious albumen. 



