CH. v] Key to Floral Characters 35 



2. Spikelets with one empty glume 1 only* 



Lolium (p. 113) has two opposite rows of spikelets, 

 L. italicum, outer palea bears terminal awn 2 . 

 L. perenne, outer palea awnless. 



3. Spikelets with two empty glumes. 



(The genera Triticum and Secale come here.) 

 Agropyrum (p. 51), rachis strongly notched. 



A. repens (p. 51), awn wanting or not exceeding 

 length of palea. 



A. caninum (p. 54), terminal awn exceeds length 

 of palea. 



Brachypodium (p. 74), rachis scarcely notched. 



B. sylvaticum (p. 74), terminal awn about as long 

 as palea. 



B. pinnatum (p. 76), terminal awn shorter than palea. 

 B. Spikelets not solitary. 



1. Spikelets in pairs, with 3-4 flowers each. 



Elymus (p. 97). 



2. Spikelets in threes, each having a single flower. 



Hordeum (p. 109). 



H. pratense, terminal awn not twice length of palea. 

 H. murinum, terminal awn twice length of palea. 



3. Spikelets in clusters. 



Cynosurus (p. 90), spike elongated ; spikelets 3-5 



flowered. 

 Sesleria (p. 131), spike short and ovoid; spikelets 2-3 



flowered. 



II. INFLORESCENCE A PANICLE. 



(Spikelets not sessile on the rachis.) 



TYPE A. Panicle cylindrical and spikelike ; spikelets one- 

 flowered. 

 1. Both palece present. 



Phleum (p. 121), glumes keeled and bear awn-point. 

 Anthoxanthum (p. 61), each flower has two pairs of 

 empty glumes, and only two stamens. 



1 The terminal spikelet has two empty glumes. 



2 Under certain conditions some of the seeds may shed their awns. 



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