. THE IDENTIFICATION OF VARIETIES OF BARLEY. 5 



Beaven in 1902 published a paper which is the most complete ar- 

 rangement of barley varieties in English. He used vulgare in the 

 place of the tetrastichum of Kornicke, divided "distichon into dense 

 and lax subdivisions, using zeocriton and distichon as parallel terms 

 to hexastichon and vulgare, and classed all deficient barleys under 

 decipiens. He included 45 new varieties produced by Karl Hansen. 

 In several instances they were not sufficiently described to determine 

 their exact character. The doubtful varieties are of necessity omitted 

 from this paper. 



The work of Kegel (1906, 1908, 1910) shows more originality and 

 less of compilation than that of most of his contemporaries. In vari- 

 ous articles appearing in the Bulletin der Bureau fur angewandte 

 Botanik and elsewhere, he has made unquestioned contributions to 

 the knowledge of barley. In his later publications Regel has made 

 his finer divisions upon what might be described as ecological races, 

 such as the Chevalier, as contrasted with the Moravian barleys. 

 Ther is very good reason for taking this position, in that it is much 

 less arbitrary in its relations than the usual taxonomic distinctions. 

 It has, however, two weaknesses. Such forms, being very difficult to 

 separate under some conditions, can be utilized only by those who 

 have made a special study of barley, and they have no limitation to 

 their increase in number. Almost any new barley calls for a new 

 division, whereas under the system proposed by the present writer 

 most additions at least will fall in a group already established. The 

 idea of geographic forms had perhaps best be carried out as an 

 agronomic rather than a taxonomic project. In his broader divisions 

 Regel has combined many previously described varieties and thus 

 broadened the terms somewhat. His modifications are well founded. 

 He recognizes only two densities instead of three, places the smooth- 

 awned forms under their nearest rough-awned relatives, and con- 

 siders blue and purple as forms of the white variety. Carleton's 

 (1916) major groups of polystichon, distichum, and intermedium 

 differ only in the rank of the deficient barleys from the scheme 

 proposed in this bulletin. 



VARIABLE FACTORS IN CULTIVATED BARLEY. 



In cultivated barleys there are six variable characters which have 

 been used in the description of varieties. These are fertility, adher- 

 ence or nonadherence of the flowering glume, the character of the 

 outer glumes, the character of terminal appendages to the lemma 

 when present, color, and density. Of these, the adherence of the flow- 

 ering glume and the character of the outer glumes have two condi- 

 tions, the terminal appendages of the lemma and density have three 

 conditions, and fertility and color have four conditions each. One 



