594 



CLXI. GRAMINEvE. 



Conspectus of the Genera. 



< Spikelets wit 



( subsimple. ( Spikelets wit 



( Both 



nilitary, ( paniculate or lobed. ( Glim 

 00, not bearded, unilateral, panic-let! 



( with awns. . t 



( in panicles, it without awns. 2 



< ( with awns. . 3 



fl-fruited, .. (in spikes, ? without awns. 4 



S with awns. . 5 



< (in panicles, ( without awns. 6 



Spikelets L 2 00-fruited, (in spikes 7 



$ Fr. white. Oryzopsls. 

 \ sessile. ( Fr. bliivk.Piptatherum. 

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



( naked. Stam. 1. Cinna. 



I herbaceous, (hairy. Stam. 3. Calamagrostis. 

 < with 1 awn, I membranaceous, 1 -keeled. . Agrostis. 

 (Paleae 2, (the lower with 3 awns, often twisted. . . Aristida. 



(Glumes J 1-flowered. ( Paleae 3, upper one with an awn. Flowers polygamous. Sorghum. 

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

 ( unequal, one of them hardly perceptible Muhtenbergia. 

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

 Glumes 0. Aquatic grasses ' Zizania. 



\ Fr. coated. Agrostis. 

 J Stig. 2. ( Fr. naked. Sporobolus. 

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

 ( PaleaB 2, ( coriaceous. . . . . . Milium. 



! Glumes 2. (Palea; 1. Panicle mostly capillary. . . Trichodi.um. 

 Glumes 0. Leaves retrorsely scabrous Lecrsia. 

 Glumes 2, very unequal, resembling the outer abortive palea?. Panicum. 

 Glumes 2, equal, longer than the palea3. . . . Phalaris. 

 $ 2. LSpikeleU 3-flowered, 2 of the flowers staminate, the other perfect. . 



( Pal. with awns 13 times their 



( Involucre 0. I Paleae with awns 5 times their length. Hordeum. 

 , Spikejets with an involucre of 2 or more bristles, 

 'ets with a burr-like involucre. 



( Both glumes and palea; awned. 

 ( Spike solitary, ( paniculate or lobed. ( Glumes awidess, palea; awned. 



< Spikes 00, not bearded, unilateral, panic-led. Palese cartilaginous. . 

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



(solitary, terminal. . 



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



n 00; spikelets sitborbicular. 



< ' digitate or verticillate, linear. 



1 pedunculate in a 2-sided panic 



( Fls. perfect or polygamous. ISpikes unilateral, (.sessile in a unilateral panicle. 



< (all terminal, sterile above, fertile at base. . . i 

 J 4. ( Spikes moncecioua, . . ( fertile ones lateral, sterile ones terminal, panicled. 1 



\ Apex bifid. Awn bent. . 

 f near the base. ( Apex multifid. 



( which has two bristly teeth. 

 I . < which is merely bifid. 



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

 ( which is entire. Fruit coated. 



- < with a cusp each side of it 



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

 Paleae entire, not mucronate, bristly at base. . 

 Paleae bidentate, outer one mucronate. . 

 Palece entire, outer one mucronate. . .. ... 



Palea; cartilaginous, outer cuspidate, coating iruit. 



Outer palea bifid and tricuspidate 



Outer palea erose-denticulate. Spikelets terete. . 



Paleae not mucronate, inner one bifid. 



Outer palea truncate-mucronate, inner bifid. . 



J perfect. . . ( Spikelets cordate at base, tumid, pendulous 



\ ( Panicle contracted. 



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



( one (in the top spikelet 2). 

 ( Glumes broad, . . ( two in each spikelet 



< ( collateral : spikelets in 2s, &c. 

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



( Spikelets in two rows. 

 { ( digitate (rarely solitary). ? Spikelets in one row. . 



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



5 7'tSpikes unilateral, (conglomerate or paniculate 



p[Q 56 _i. Agrostis alba ; a 1-flowered spikelet ; a, the two glumes. 2. A flower, with the twopaleae, 

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

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

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

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

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

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

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



( Spikelets 

 fTerminal fl. < not cordate. 



