38 Botanical Section [pt i 



Festuca <pratensis (p. 100), spikelets 5-6 flowered; 



O.P. 5-8 mm. long. 

 Glyceria aquatica (p. 104), aquatic ; spikelets 5-10 



flowered. 

 Catabrosa aquatica (p. 90), aquatic; spikelets 



2-flowered. 

 Briza (p. 77), large inflated spikelets 6-8 flowered. 

 Melica nutans (p. 116), two perfect flowers in 



each spikelet. 



CHAPTER VI 



KEY TO GRASS "SEEDS" 



It has been found most convenient to classify the "seeds" 

 of grasses in the main by the presence or absence of an awn on 

 the outer palea. In Group I are placed all "seeds" which are 

 distinctly awned, i.e. having on an average awns exceeding half 

 the length of the palese bearing them. In Group III the palese 

 bear no trace of an awn; the apex of the outer palea is either 

 rounded off, or is acutely pointed, but does not taper off into 

 a long point. 



Group II is intermediate in these respects between Groups I 

 and III, and includes "seeds" in which the apex of the outer 

 palea either 



(a) tapers to an awn-point; 



(b) bears a sub-terminal point or spur: 



(c) is two to five-toothed. 



The terms "awn" and "awn-point" are of course only relative. 

 If on an average the awn -like projections exceed half the length 

 of the palese bearing them they are considered as awns ; if they 

 do not exceed this they are termed awn-points. In the case of a 

 few species, where the length of the awn-point is subject to wide 

 variation, the seeds have been included in more than one Group. 

 The awn — when present — affords several other useful distinctive 

 characters. It may arise from either the base (basal) or apex of 

 the outer palea (terminal awn). Or it may arise from a point 



