104 THE WHEAT PLANT 



being seen also in some forms of T. polonicum. The hairs of T. Spelta 

 in some cases are stout, and of nearly uniform size -4- -6 mm. long ; in 

 a few forms, stout hairs -4 mm. long are mixed with stout short ones 

 12 mm. long. 



In dimensions the hairs on the glumes of T. compactum agree some- 

 what closely with those of T. turgidum. 



Inserted alternately on opposite sides of the short rachilla are the 

 flowering glumes, in the axils of which the flowers arise. They are boat- 

 shaped, many-nerved, and without keels, the upper part notched and 

 ending in a point or a long awn, the length of which usually increases in 

 the spikelets near the tip of the ear. 



The awns are tapering and triquetrous, with forward pointing scab rid 



projections running longitudinally along the angles ; they are generally 



straight, but may be sinuous or even bent into the form of a hook or spiral, 



as in some Asiatic forms of T. vulgare. In a Persian form of T. vulgare 



the awn has a pair of thin membranous and colourless outgrowths (Fig. 217). 



The separation of wheat into " bearded " and " beardless " kinds was 



Y made as soon as the classification of the cereal was attempted, the two 



groups being characterised respectively by the presence or absence of a 



long beard or awn on the flowering glumes of the ear. 



In the bearded wheats, long awns occur on the flowering glumes of 

 all the spikelets from the base to the tip of the ear, the longest being a 

 little above the middle of the ear, the shortest at the base and apex. The 

 two lower flowering glumes of each spikelet have awns nearly equal in 

 length and fully developed, the third and succeeding glumes having 

 shorter awns which are frequently reduced to a fine point, especially when 

 the subtended flower produces no grain. 



Strictly beardless wheats entirely without awns are of exceptional 

 rarity. I have met with them only in a small group of Indian, Japanese, 

 and Australian forms of T. vulgare, which I have little doubt are genetically 

 related ; in these, the flowering glume terminates in a short tooth, like 

 that of the empty glume 



The term " beardless " is, however, used not only for those wheats 

 in which awns are altogether absent, but for many hundreds of forms 

 having short points or greatly reduced awns, usually not more than i cm. 

 in length, confined to the tip of the ear. In a small percentage of cases 

 one or two awns on the terminal spikelets reach a length of 2-5 cm., but 

 the difference between bearded and beardless varieties is fundamental, and 

 there is no difficulty in assigning any ear to one or other of these two 

 classes, except, perhaps, in the case of rare, unstable hybrid forms in which 

 awns of intermediate length sometimes appear over a considerable length 

 of the ear. 



In truly bearded ears the awns are uniformly distributed from the top 



