HOW TO KNOW THE GRASSES 



26a. Spikelets with two similar ilorets, the 



lower staminate and with a bent awn, 



the upper perfect and with a short 



straight awn 



..see Fig. 179. (ATrhenatherum elatius) 



26b. Spikelets with a single perfect floret and 

 1 or 2 unlike staminate or sterile florets 



or little scales borne below it 



...Fig. 38. TRIBE VIIL PHALARIDEAE, 



page 144 



Figure 38 



27a. Spikelets borne in one or more spikes, sessile or rarely on short 

 pedicels less than 1 mm. long 24 



27b. Spikelets in open or dense panicles, each spikelet on a pedicel . . 28 



28a. Glumes not reaching above the tip of the 



lowest floret; lemmas awnless or with one or 



more awns arising at the tip or between teeth. 



Fig. 39 TRIBE 11. FESTUCEAE, page 23 



28b. Glumes reaching beyond the tip of the lowest 



floret and usually beyond the uppermost floret; 



lemmas awnless or with a single awn arising 



from the back or between two teeth. Fig. 40 ... 29 



29a. Sheaths with imited edges 



TRIBE 11, FESTUCEAE, page 23 



Figure 39 



29b. Sheaths with overlapping edges. 



30 



30a. Lemmas with 3 prominent, conspicuously hairy 

 nerves, all 3 extending into short awns — see Fig. 

 52 and following, (genus Tridens) 



30b. Lemmas not as above. 



31 



Figure 40 



31a. Tall stout grasses 1 — several m. tall; lemmas or rachilla joints 

 covered with long straight hairs which conceal the spikelets 

 TRIBE II, FESTUCEAE, page 23 



31b. Grasses of small to moderate stature, seldom over 1 m. tall; lem- 

 mas and rachilla joints smooth or hairy, but not concealed by 

 long hairs TRIBE IV, AVENEAE, page 95 



22 



