22 FIRST BOOK OF GRASSES 



as long as the florets themselves; the node at the 

 base of the floret (the callus) is sometimes prolonged 

 into a sharp point; the uppermost rachilla joint may 

 bear no floret and may extend into a little bristle. 



(5) The glumes may vary in shape, in texture, 

 and in the number of their nerves and may be gla- 

 brous (smooth) or pubescent (hairy) ; sometimes they 

 are reduced to rudiments and sometimes they are 

 suppressed. 



(6) The lemma is subject to such great modifica- 

 tions that we shall now note only the simplest ones. 

 As in the glumes, the shape and texture and the 

 number of nerves vary. The summit of the lemma 

 may be acute (pointed) or acuminate (long-pointed) 

 or obtuse (blunt) or it may be lobed or cleft. The 

 nerves may be faint or strong, or may extend into 

 awns (bristles) beyond the body of the lemma. The 

 lemma is sometimes minute, but it is never sup- 

 pressed. 



(7) The palea is always 2-nerved, but in a few 

 grasses the nerves are so close together as to appear 

 like a single one. In others they are far apart and 

 the palea may split between them. The palea differs 

 in size and texture. In a few genera it is reduced or 

 even suppressed. 



(8) Spikelets are compressed (flattened) laterally 

 (sidewise), as in Figs. 11-14, or dorsally (on the 

 back), as in Figs. 60-66. The side or back of a 

 spikelet is recognized from the position of the florets 

 on the rachilla. The palea side of the floret is always 



