1 8 Graminaceae 



Tribe 5. Aveneae. Spikelets 2-many-flowered. 

 Flowering glumes usually shorter than the two empty 

 glumes^ usually with dorsal, rarely apical, bent and 

 twisted awn. 



A. Spikelets falling as a whole, Holcus. 



B. Flowering glumes in fruit becoming detached 

 from the persistent empty glumes. 



a. Rachilla not produced. 



Flowering glumes awned, 2-toothed. Aira. 



fi. Rachilla produced. 



Flowers 2, awn bent in middle, tip<;lavate. 



Corynephorus. 



Flowers 2, awn straight, acute. Deschampsia. 



Flowers 2-6, flowering glumes deeply bifid with 

 twisted awns. Trisetum. 



Flowers 2-6, flowering glumes entire or 2-toothed 

 with long awns. Avena. 



Flowers 2, upper hermaphrodite, lower ^. 



Arrhenatherum. 



Tribe 6. Festuceae. As Aveneae hut floivering ghimes 

 usually longer than the two empty glnmes. Awn absent, 

 or apical and straight. 



a. Spikelets 2 or more flowered : rachilla not 

 bearded. Flowering glumes with three broad teeth. 



Sieglingia. 



^. Spikelets 2 or more flow^ered : rachilla with 

 silky hairs. Phragmites. 



7. Spikelets subspicate or capitate, with imperfect 

 spikelets on pedicels below them. 



Imperfect spikelets ciliate. Sesleria. 



Imperfect spikelets with stifl" bristles. Cynosurus. 



