ORIGIN AND RELATIONSHIPS OF RACES OF WHEAT 341 



THE RIVET OR CONE WHEATS (T. turgidum. L.) have the characters 

 of a hybrid race produced probably within historic time by the crossing 

 of the tall European T. dicoccum with T. compactum or a dense-eared 

 form of T. vulgare. 



Its affinity with the European Emmer can be traced in its morpho- 

 logical characters and habit. The two races agree in the characteristic 

 pubescence of their young leaves. Both have tall, solid or nearly solid 

 culms, and ears with spikelets very regularly arranged along the rachis. 

 They tiller very little and have a similar late-ripening period. 



Sloreover, the tendency to produce branched ears is strongly evident 

 in these two races and rare in others. 



The square ear of T. turgidum, its many-flowered spikelets, and 

 plump, blunt-ended grain are characters derived from the dense-eared 

 compactum or ru/gare parent, the dorsal hump of the grain being derived 

 from the Emmer parent. 



In its typical form the Rivet race is endemic only in the area in which 

 T. dicoccum and T. compactum are present, namely, along the northern 

 side of the Mediterranean from Portugal eastward to the Caucasus, where 

 it is found sporadically distributed and hardly typical. It is absent from 

 Asia Minor, Persia, India, and China, in which countries either one or 

 both of the presumed parents are missing. 



The solitary case from Baluchistan reported by Howard requires 

 further investigation. Forms bearing some resemblance to 7'. turgidum 

 I have received from the Central Provinces and Bombay ; those, of which 

 " Bansi " of Hoshangabad is a good example, are only endemic in the 

 provinces where T. dicoccum is grown and are probably hybrids of this 

 race with T. durum. 



EGYPTIAN CONE WHEAT (T. pyramidale, mihi) is a small but distinct 

 race confined to Egypt and Abyssinia. I regard it as an endemic dense- 

 eared mutation derived from the Abyssinian form of T. dicoccum. It 

 exactly agrees with the latter in the pubescence of its young leaves, yellow- 

 green culm-leaves, short culms, very early habit, and the shape of its 

 grain, and only differs from it in having short, dense ears with a tough 

 rachis. 



SERIES III.- The Bread Wheat scries includes Bread Wheat, Dinkcl 

 or Large Spelt, Club and Indian Dwarf wheats. 



THE BREAD WHEATS (T. rulgare, Host). It is in regard to the origin 

 and relationship of the members of this series that the greatest diversity 

 of view is found among those who have studied the subject. The search 

 for a prototype possessing the characters of the wlgare race has been 

 diligently pursued from the earliest times, but nothing approximately 

 like it has been found growing wild. That another primitive species. 



