120 



THE SMALL GRAINS 



112. The flower in the fertile spikelet usually is 

 sessile, in the sterile spikelets pedicellate. The lemma 

 is ovate, broad arched, 5-nerved, somewhat angled at the 

 nerves, glabrous, sometimes having purple or brownish 

 purple stripes, especially in two-row varieties, which disap- 

 pear in ripening, drawn out into a long, stiff, straight 

 awn. The inner pair of side nerves has, in some 

 cases, numerous small translucent 

 teeth ; in other cases smooth. This 

 is a distinguishing character, and 

 has been used in separating groups. 

 Another group character is the 

 nature of the base of the lemma. 

 Just above the line of attachment 

 of the lemma to the rachis, on the 

 dorsal side, there is, in the two-row 

 nutans group, a slight horseshoe- 

 shaped depression. In the two- 

 row erectum group the dorsal side 

 of base is not depressed, but there may be a transverse 

 crease. The same differences are found in six-row barley. 

 The awns are longer in the middle spikelet than in the 

 lateral spikelets, , flat on the inner side, flat, angled, or 

 arched on the outer side, usually smooth on the surface, 

 but much roughened on the margins by rigid, pointed 

 teeth. They include a continuation of the middle nerve 

 and the two nearest side nerves of the lemma. In rare 

 varieties the lemma is without awns, and merely pointed. 

 Such forms occur sometimes in hybrids. In the hooded 

 barleys there is a trifurcate appendage in place of the 

 awn, one of the segments being hood-shaped. The palea 

 is obtuse, glabrous, two-keeled or two-nerved, arched 

 inward between the keels and turned in at the margins. 



FIG. 36. Barley kernels 

 showing the two kinds 

 of basal bristles : on 

 left, the curly bristle; 

 on right, the straight- 

 haired bristle, X 2. 



