21 



Jour., Bom. Nat. Hist. Soc, Vol, XXXIV, No. 1 [March 1, 1930 



firmer, 5-or more nerved, rarely 3-nerved ; awn, if 

 present, from the back or sinus or between bristles, 



a. Floral glumes awn less or awned from 



the back ; florets 2 or more, the 

 uppermost reduced. 



(1) Spikelets 2- or more-flowered, 



awned (vol. 33, 234) ... ... 64. Avena. 



(2) Spikelets 2-flowered, awnless (vol. 



33, 235) ... ... ... 65. Coelachne. 



b. Floral glumes awned from the sinus of 



the bifid tip ; florets 3 to many, the 

 uppermost reduced (vol. 33, 236) ... 66. Danthonia. 

 TRIBE VI : Arundineve. — Florets 2-many, enve- 

 loped in very long hairs, springing either from the 

 callus or from the back or margins of the floral 

 glumes. 



a. Hairs springing from the margins of 



the upper floral glume (vol. 33, 234). 67. Thysanolaena. 



b. Hairs springing from the callus (vol. 33, 



236) " ... ... ... 68. Phragmites. 



c. Hairs springing from the involucral 



glumes (vol. 33, 237) ... .. 69. Arundo. 



ii. Florets 1 (Genera 70-78). 

 TRIBE VII: Agroste.?e. -Floret 1. Rhachilla 

 rarely produced beyond the floret ; upper floral 

 glume membranous, not changed when mature, 

 usually 5-nerved, all the nerves or the outer side- 

 nerves often slightly excurrent, parallel or at least 

 not anastomosing. Spikelets awned or not. 



a. Spikelets in cylindric spike-like pani- 



cles, not awned (vol. 33, 237) ... 70. Heleochloa. 



b. Spikelets in open or contracted many- 



flowered panicles, awned. 



(1) Involucral glumes acuminate or 



awned (vol. 33, 238) ... ... 71. Garnotia. 



(2) Involucral glumes awned from the 



. ' notched or lobed tips (vol. 33, 237)... 72. Polypogon. 



TRIBE VIII: Stipes.— Floret 1. Rhachilla not 



produced beyond the upper floral glume which is 



bisexual, hardened when mature, tightly enveloping 



; nerves joining or closely approaching at 



Awn terminal, rarely absent. 



Awns 3, from the entire tip, or 1, sim- 

 ple below and 3-branched above, 

 very rarely quite simple (vol. 33, 

 238) ... ... ... 73. Aristida. 



ZoysiEuE. — Floret 1. Mature spikelets 

 falling entire and singly, or in clusters. Rhachilla 

 not continued beyond the floret. Involucral 

 glumes equal or the lower much smaller or sup- 

 pressed. Floral glume small, delicately membra- 

 nous, 3-1-nerved ; spikelets in slender spiciform 

 panicles or racemes (Genera 74-78). 



a. Spikelets falling in clusters of 2-4, 

 fascicled. 



(1) F'ascicles secund on a broad articu- 

 late rhachis ; glumes 4 ; upper 

 involucral glume not echinate (vol. 

 33, 480) ... ... ... 74. Trachys. 



(2) Fascicles all round a slender 

 rhachis ; glumes 3 ; upper involu- 

 cral glume echinate (vol. 33, 480)... 75. Nazia. 



b. Spikelets falling singly. 

 (1) Lower involucral glume with pecti- 

 nate margins ; upper involucral 



[10] 



the fruit 

 the tip. 



TRIBE IX 



