594 



CLXI. GRAMINEiE. 



Conspectus of the Genera. 



i with awna. . 1 1 



f in panicles, ^ without awns. | 2 



< (with awns. . §3 



r l-frxiited, . . ( in spikes, i without awns. § 4 



I S with awns. . § 5 



i < in panicles, ( without awns. | 6 



Spikelets La— 00-finiited, (in spikes §7 



iFrwtute.Oryzopsis. 4 



\sesai\e. iFr.black.Piptatherum. 3 



rcartilaginous, (stipitate. Fr.h]a.ck St ipa. 2 



J 4 naked. Stam. 1. Cinna. 10 



I herbaceous, \ hairy. Stam. 3. Calanmgroitis. 13 



< with lawn, I membranaceous, 1-keeled. . Agrostis. 5 



4 PaleiE 2, (the lower with 3 awns, often twisted. . . Aristida. I 



I Glumes 5 l-flowered. ( Paleas 3, upper one with an awn. Flowers polygamous. Sorghum. 57 



large, J 2-flowered (one flower abortive), longer than the palei. . . . Holcus. 25 



4 unequal, one of them hardly perceptible Muhlenbergia. 9 



Glumesminute, (subequal, one of them awned Trichochloa. 11 



Glumes 0. Aquatic grasses Zizania. 59 



<Fr. coated.. 4g7osi(s. 5 



5 Stig. 2. ( Fr. naked. Sporobolvs. 6 



< membran'ous. ( Stigmas 3. . . Psamma. 12 



< PalesE 2, ( coriaceous Milium. 19 



5 Glumes 2. ( Paleae 1. Panicle mostly capillary. . . Tridiodium. 3 



("Spikelets l-flowered. { Glumes 0. Leaves retrorsely scabrous Leeisia. 58 



J i Glumes 2, very unequal, resembling the outer abortive paleae. Panicuni. 21 



1 Spikelets 2-flowered. \ Glumes 2, equal, longer than the paleae. ... Phalaris. 24 



:. I Spikelets 3-flowered, 2 of the flowers staminate, the other perfect. . . Hierochloa. 26 



4 Pal. with awns 1 — 3 times their length, ^iopccwrii*. 14 



( Involucre 0. \ Pales with awns 5 times their length. Hordeum. 53 



■^ Spikelets with an involucre of 2 or more bristles. Setaria. 22 



f subsinjple. ( Spikelets with a burr-like involucre. . . . Cenchrus. 23 



< 4 Both glumes and paleae awned. . . Polypogon. 7 



C Spike solitary, ( paniculate or lobed. ( Glumes awnless, palea; awned. . . Anthoxanthv/m. ^ 



< Spikes 00, not bearded, unilateral, panicled. Paleie cartilaeinous. . . . Oplisnienus. 20 



1. ( Spikes 2 — 00, polygamous. Sterile flowers plumosely bearded. . . . Andropogon. 56 



i solitary, terminal. . . . Phleuni. 16 

 'Spikes cylindrical, ( several, terminal and lateral. Crypsia. 



%i 



§5 



r 1—00 ; spikelets suborbicular. Paspalum. 



.' digitate or verticillate, linear. Digitaria. 

 I pedunculate in a 2-sided panicle. Sparftna. 



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



< J all terminal, sterile above, fertile at base. . . Tripsacum. 



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



i Apex bifid. Awn bent. . Averta. 

 f near the base. ( Apex multifid. 



which has two bristly teeth. 



f Spikelets 

 f Terminal fl. ^ not cordate 

 ) perfect 



J" Spikes 2-ranked, 



which is merely bifid. 

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

 J i which is entire. Fruit coated. 



1 \ with a cusp each side of it. . 



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

 'Paleae entire, not mucronate, bristly at base. . 

 Paleae bidentate, outer one mucronate. . 

 PaleK entire, outer one mucronate. . 



Paleae cartilaginous, outer cuspidate, coating iruit, _ 



Outer palea bifid and tricuspidate Tricuspis. 



Outer palea erose-denticulate. Spikelets terete. . Glyceria. 



Paleae not mucronate, inner one bifid. . . . Poa. 



L Outer palea truncate-mucronate, inner bifid. . . Unioia. 



( Spikelets cordate at base, tumid, pendulous. .... Briza. 



I 4 Panicle contracted. . . . Koeleria. 



LTerminal flower abortive or a mere pedicel. (Panicle large, diffuse. . . Melica. 



i one (in the top spikelet 2). . . . Lolium. 



Glumes broad, . . ( two in each spikelet Triticwm. 



S collateral ; spikelets in 2s, &c. . . Elymus. 



Glumes subulate, ( opposite ; spikelets solitary. . . . Secale. 



I 5 Spikelets in two rows. . . Eleiisine. 



! (digitate (rarely solitary). (Spikelets in one row. . . . Cynodon. 



I <. remote, short, forming a long, slender raceme. . . . Atheropogon. 



I. Spikes unilateral, ( conglomerate or paniculate Dactylis. 



§7. 



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

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

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

 a l-flowered spikelet; a, glumes ; J, truncate palea; ; &c. 5. Polypogon; a l-flowered spikelet ; glumes 

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

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

 two paleie, &c. 8. Festuca duriuscula ; a 5-flowered spikelet : re, two glumes; 6, a single flower. 9. The 

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



