*>38 on.vMiNF^E. (GRASS FAMILY.) 



37. BROMUS. Lower palea convex or keeled on the back, mostly awned or bristle-beurinj: ' c- 



low the 2-cleft tip, 5 - 9-nerved. Styles j-ub terminal. 



* * Culms herbaceous, often tall and reed-like. Lowest flower sterile. Grain free. 

 N iOLA. Spikclets very flat ; the one or more lowest flower? neutral, of a single empty 

 pnlca Flowers strongly compressed keeled, crowded, coriaceous. 



39. PHRAG M J TE8. Spikelets strongly silky -bearded on the rhachis, loosely-flowered, the low- 



est flower staminate or neutral. Paleae menibranaceous. 



* * * Culms woody, suffruticose or arborescent. 



40. ARUNDINARIA. Spikelets flattened, loosely 5-14-flowered : the jointed rhachis naked. 



Bubtribe 5. HOKDEINE^E. Spikelets 1 - several-flowered, sessile on opposite sides of a zigzag 

 jointed rhachis (which is excavated or channelled on one side of each joint), forming a 

 Bpikt . Glumes sometimes abortive or wanting. Otherwise as in the preceding subtribo 

 .* Spikelets single at each joint of the rhachis, 1- flowered. Spikes often several. 



41. LEPTURUS. Spikelets almost immersed in the excavations of the slender rhachis. 



* * Spikelets single at each joint of the rhachis, several-flowered. Spike solitary. 



42. LOLTUM. Glume 1, external : spikelets placed edgewise on the rhachis. 



43. TRITICUM. Glumes 2, transverse (right and left) ; spikelets placed flatwise on the rhachlfi. 



* * * Spikelets 2 or more at each joint of the rhachis. Spike solitary. 

 i- Glumes anterior, forming a sort of involucre for the cluster of spikeleta 



44. HORDE UM. Spikelets 1-flowered, 3 at each joint, but the two lateral usually sterile. 



45. ELYMUS Spikelets 1 - several-flowered, all perfect and similar. 



- H- Glumes none or 1 - 2 awn-like rudiments. 

 40. GYMNOSTICHUM. Spikelets few-flowered, somewhat pedicelled, 1 - 3 at each joint. 



Snbtribe 6. AVENE*;. Spikelets 2 - several-flowered, pamcled ; the rhachis or base of tha 

 flowers often villous-bearded. Glumes mostly equalling or exceeding the flowers. Low- 

 er palea bearing a twisted, bent, or straight awn on its back or below its apex (hi No. 48 

 between the teeth) ; the upper 2-nerved Stamens 3. 



* Flowers all perfect, or the uppermost merely rudimentary. 

 - Lower palea truncate or obtuse, its summit mostly denticulate or eroded. 



47. AIRA. Awn on the back or near the base of the palea, bent or straight. 



- +- Lower palea cleft at the apex into 2 acute or sharp-pointed teeth. 

 ** Awn borne between the sharp or awn-pointed teeth ; proceeding from 3 middle nerve*. 



48. DANTIIONIA. Lower palea rounded on the back ; the awn flat, spindly twisted. 



+* -H- Awn below the apex or dorsal, proceeding from the midnerve only. 

 48. TRISETUM. Lower palea compressed-keeled. Awn mostly bent or flexuous. 

 50. AVENA. Lower palea rounded on the back. Awn mostly twisted or bent.. 



* * One of the flowers staminate only. 

 f>l. ARRHENATHERUM. Lower flower stamiuate ; the perfect one commonly awnless ; the 



uppermost a rudiment : otherwise as No. 50. 



fj2. HOLCUS. Lower flower perfect, awnless; the upper staminate and awned: rudiment 

 none. 



TRIBE II. PHAI^ARIDE^E, Trin. (not of Kunth). Spikelets 3-flowered : the upper- 

 most or middle (terminal) flower perfect; the two lower (one on each side) imperfect, 

 either staminate, neutral, or reduced to an inconspicuous rudiment. 



Subtribe 1. AMHOXAMIIE.S. Lateral flowers mostly awned, staminate or neutral, of 1 or 2 



paleuo ; the perfect one awnless and diandrous. Upper palea 1 -nerved. 

 5-. IIIKItOCIiLOA Lateral flowers staminate and triandrous, of 2 paleae. 



54. ANT110X ANTHUM. Latmil flowers neutral, each of a single awned palea. 



Subtribe 2. PUALARIDK/I: I'l-opor Lateral flowers reduced to a small neutral rudiment on 

 each side of the fertile one ; which is awuless and triandrous. 



55. PHALAHIS. < Mimics hoat-shap. <1. keeled, enclosing the coriaceous fertile flower, which is 



somewhat flattened laterally. 



