SB 191 
 .B2 H2 
 Copy 1 
 
 UNITED STATES DEPARTMENT OF AGRICULTURE 
 BULLETIN No. 622 
 
 Contribution from the Bureau of Plant Industry 
 WM. A. TAYLOR, Chief 
 
 Washington, D. C. 
 
 PROFESSIONAL PAPER 
 
 February 2, 1918 
 
 THE IDENTIFICATION OF VARIETIES 
 OF BARLEY 
 
 By 
 
 HARRY V. HARLAN, Agronomist in Charge of Barley 
 Investigations, Office of Cereal Isivestigations 
 
 CONTENTS 
 
 Page 
 1 
 3 
 
 5 
 
 Varieties of Barley 
 
 Review of the Literature 
 
 Variable Factors in C;:Uivated Barley . 
 
 Scheme of Classification 8 
 
 Lines for Further Study . 25 
 
 IdentificaUon of Thrashed Material . . 26 
 
 Page 
 Varieties Grown in Field Culture in the 
 
 United States 28 
 
 Key to Commercial Varieties 28 
 
 Sumnary 30 
 
 Literature Cited s 31 
 
 WASHINGTON 
 GOVERNMENT PRINTING OFFICE 
 
 1918 
 
 Monograph 
 
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UNITED STATES DEPARTMENT OF AGRICLTTUEE 
 
 A BULLETIN No. 622 ^ 
 
 ContiibotiiMi firaai the Bore;^^ 
 WM. A. TAYLOB, 
 
 P:^-: l-ixL-zr7 
 
 
 WashingtorL D. C. 
 
 PROFESSION'AL PAPEE 
 
 February 2. 1918 
 
 THE IDENTIFICATION OF VARIETIES OF B.ARLEY. 
 
 By Hakrt V. Haslax, Agronorf»iit in > 
 
 igations, Oj^ee of Cereal 
 
 CONTENTS. 
 
 Varieties of Barter 1 , 
 
 Review of the literature 3 ! 
 
 VariaUe factors in cultivated barley 5 | 
 
 Fertility 6 j 
 
 Adberence of the flowering ^oHie 6 
 
 Outer glumes 6 
 
 Terminal appendages of the femma ~ | 
 
 Cofcw 7 I 
 
 Density * ! 
 
 Sdioneofeiasafication. s 
 
 The speeies<rfeattiTated barley 10 ' 
 
 Key to the qndes. 12 I 
 
 Scheme of ciassi&catian— Continnfid- 
 
 Key to the varieties -... 14 
 
 Key to the sabvarieties- 16 
 
 B^ertedspeeies,sat)6peeies,andTarietie> 23 
 
 Lids for fiorther study 25 
 
 Identifieatian of thrashed material 26 
 
 V ar ie ti e s grown in field cnltnre in the TTnited 
 
 States 25 
 
 Key to euiumercsal varieties 2S 
 
 Sonnnary 30 
 
 Literature cited 31 
 
 VARIETIES OF BARLEY. 
 
 This bulletin has been prepared primarily to meet a widespread de- 
 mand for a publication on the forms of barley. Although advantage 
 has been taken of the opportTinity to call attention to a number of new 
 forms, the main object has been to satisfy the demand fromexpeiiment- 
 station workers and advanced students in agronomy for an outline 
 of the cultivated barleys. This demand can lie traced to three 
 causes — the many new forms of barley annually added to f>ur collec- 
 tions, the broadening field of genetic and agronomic studies, and the 
 confusion in and lack of availability of the literature on the forms of 
 barley. 
 
 The increase in the number of barley varieties has been rapid. Not 
 only have many new sorts been produced by the various agricultural 
 experiment stations, but there has been a large number of importations. 
 These importations have been of many types and of themselves have 
 
 146S1=— IS— BoU. ♦J22 1 
 
2 BULLETIN 622, U. S. DEPARTMENT OF AGRICULTURE. 
 
 done much to stimulate interest in barley. At the same time a demand 
 for more detailed information on all our crops has developed. Plant 
 problems, especially studies in variations and inheritance, are being 
 persistently attacked. When this new interest was directed toward 
 barley, it immediately became apparent that this crop, because of 
 the unusual clearness of the varietal distinctions, was exceptionally 
 well suited both to student instruction and to genetic studies. This 
 clearness comes in part from the very broad limits of the gi'oup. 
 The variable characters are numerous and the separations sharp. 
 Few cultivated crops present such contrasts as hulled and naked 
 kernels,^ awned and hooded lemmas, fertile and infertile lateral 
 florets, etc. The number of factors, coupled with the fact that all 
 forms are perfectly fertile when crossed with each other, has resulted 
 in a large number of easily distinguished varieties. The relative 
 ease of subdividing the species makes the crop a profitable one to the 
 student, and the definiteness of its varieties makes it equally useful 
 to the plant breeder. 
 
 The lack of available literature and the confusion existing as to 
 the identity of the various forms have been a real handicap to stu- 
 dents and plant breeders alike. Studies in crop plants must include 
 a comprehensive summary of the forms and types of each crop. This 
 is a necessity for that familiarity with the crop which both student 
 and agronomist should possess and is essential to a proper under- 
 standing of the publications of others dealing with the subject. 
 
 At present American literature contains no such summary. In- 
 deed, the only work in English which attempts to present a complete 
 arrangement of the forms is Beaven's "Variety of Barley"" (1902).^ 
 This is out of print and is to be found in very few libraries. In 
 French there are the works of Heuze (1872, 1896-97), and in Ger- 
 man those of Kornicke and Werner (1885), Voss (1885), and Atter- 
 berg (1899). The utilization of these and other more fragmentary 
 publications is difficult. Frequently they are not available, and even 
 if at the disposal of the investigator they present as many different 
 methods of treatment as there are authors. In some instances the 
 departures are so revolutionary that serious confusion has resulted. 
 
 The aims of this paper are (1) to coordinate the various schemes 
 of classification and to reconcile them as far as possible, (2) to make 
 available the work that has already been published on barley and 
 to suggest modifications to obtain a more logical arrangement of the 
 varieties, (3) to add the several new forms of barley which have been 
 
 ^The word kernel is used throughout this publication to indicate the naked kernel 
 (caryopsis) in the naked varieties and the keniel with lemma and palet attaclied 
 (earyocist) in the hulled varieties. It was found too cumJjereome to use the more limited 
 terms, as they required repeated explanations. 
 
 - For complete citations, see " Literature cited," p. 31. 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 3 
 
 discovered during the progress of the work, and (4) to form the 
 basis for a discussion of all the agricultural varieties grown upon 
 the farms in America. 
 
 There is also a distinctly experimental phase to the work. Cer- 
 tain types of barley are likely to succeed in certain areas, while others 
 are as definitely unsuited to specific regions. A more thorough co- 
 ordination of the work of the various stations with reference to types 
 of varieties should be of service in experimentation. It is possible 
 also that a study of the existing forms of barley may be useful to 
 pathologists in determining the degi'ces of immunity to disease of 
 the various groups. 
 
 REVIEW OF THE LITERATURE. 
 
 Although the genus Hordeum to which the cultivated barleys be- 
 long obtains its name direct from the Latin name, there is little to 
 be gained in a revicAv of the literature before Linna?us. Almost all 
 of the pre-Linna?an authors recognized the distinction between 2- 
 rowed and 6-rowed barleys. Linnaeus (1753, p. 84-85), amplifying 
 his scheme of 1748, described six forms, four species and two varie- 
 ties, viz : 
 
 Hordeum rulgare. Hordeum dhtiehon. 
 
 Hordeum vuli/arc coeleste. Hordeum distiehon nudum . 
 
 Hordeum he.rastiehon. Hordeum zeoci'iton. 
 
 Gustav Schuebler (1818) named seven species, using in their sepa- 
 ration fertility, color, adherence of flowering glumes, and density. In 
 this work he made for the first time the distinction between nutans 
 and erectuni. These were subdivisions of distiehon and not of the 
 rank of the seven species. 
 
 Seringe (1819) suggested four species, hexastlchon^ indgare^ zeo- 
 cnton^ and flistiehon. In 1841 he followed closely the scheme of 
 Linnaeus, although he made several subdivisions. 
 
 LTp to and including Seringe, all treatments were based upon 
 limited collections. iVs a greater number of varieties were assem- 
 bled, the problem of classifying them called for a marked expansion 
 of the systems. The first of the more modern treatments was that 
 of Heuze in 1872. This w^as really a remarkable contribution, and 
 in both arrangement and material was the obvious forerunner of 
 both "Die Saatgerste " of Kornicke (1882) and of the treatment 
 in the " Handbuch des GetreideJDaues '" of Kornicke and Werner 
 (1885) . '" Die Saatgerste," as later amplified under the title of " Die 
 Arten und Varietaten des Getreides" in the "Handbuch des Ge- 
 treidebaues '' (Bd. 1), has been widely accepted as the best modem 
 authority. In part this credit is well bestowed. Kornicke used the 
 variety as a unit, and although he sometimes went too much into 
 
4 BULLETIN 622, U. S. DEPARTMENT OF AGRICULTURE. 
 
 detail, his conception of varieties was such as to establish most of 
 them upon a firm basis. His treatment of the larger groups, on the 
 other hand, was less satisfactory. He recognized hexastichon^ 
 tetrastichum^ intermedium, and distichum as his primary groups. 
 These are more fully discussed later. A third paper appeared in 
 1895, and in 1908, after his death, his son, M. Kornicke, published 
 a fourth treatment. Neither of these latter possesses the clearness 
 of the earlier papers, and they include many doubtful varieties. 
 Many of the additions were of hybrid origin and were unfixed at 
 the time of publication. Kornicke's failure in many instances was 
 due to the general lack of genetic information at that time. Recent 
 discoveries have made the purification of a type rather simple. For 
 instance, his suhcomutufm was selected from a mating of trifurcatv/m 
 and steudelii and was far from fixed. A constant variety of this 
 type is readily obtained from a cross of comutum X pallidum or of 
 horsfordianuTTi X haxtoid. Many varieties attributed to Kornicke in 
 the key which follows were heterozygous forms with him which he 
 was never able to fix. Most of these have been recognized in this 
 publication, because fixed forms corresponding to the descriptions 
 have since been produced. 
 
 In 1885, the year in which the " Handbuch des Getreid«baues " Avas 
 published, a paper by Voss appeared. Voss follows Jessen (18,55) 
 and places all cultivated barleys under the single species Hordewm 
 sativum. Although his handling of the varieties is inferior to that 
 of Kornicke, his treatment of the larger groups is decidedly better. 
 He uses polystichou, distichon, and dejicieiis as his subspecies. He 
 indicates that dejlciens is subject to the same variations as disticTwn 
 by subdividing it into dense and lax divisions. Pie substitutes in- 
 equale for the term tetrastichum of Kornicke, pointing out that there 
 is no such thing as a 4-rowed barley, 
 
 Following Voss came Atterberg, who published various papers 
 between 1889 and 1899. In the latter year he advanced a neAv basis 
 of classification. He made four subspecies under Hordeum. sativum 
 Jess., namely, comMiune, maGrolejns, furcatumy, and inerme. As 
 both the character of the outer glumes and the appendages to the 
 lemma were used, the result was rather involved and seems to offer 
 little compensation for so abrupt a departure. Atterberg's concep- 
 tion of the regular occurrence of the subfactors through each of 
 the groups gives evidence of a familiarity with a larger number of 
 varieties than had been accessible to previous taxonomists. His sys- 
 tem of uniform recurrence of names in his subgroups seems inad- 
 visable and likely to lead to confusion, even though, as he points 
 out, he uses only 33 terms to designate 188 forms, while Kornicke 
 used 78 terms to designate 74 varieties. 
 
THE IDENTIFTCATTON OF VARTETIl^.S 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 tetrastlchuvi ot Kornicke, divided 'distlchon into dense 
 and lax subdivisions, using zeocnton 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 sexeral instances they were not sufficiently described to determine 
 their exact character. The doubtful \arieties 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 fiir angewandte 
 Botanik and elsewhere, he has made unquestioned contributions to 
 the knowledge of barley. In his later publications Kegel 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 })roposed 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 
 Kegel 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 polystlchon^ distichimi, 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 apjjendages of the lemma and density have three 
 conditions, and fertility and color have four conditions each. One 
 
6 BULLETIN 622, U. S. DEPARTMETSTT OF AGRICULTURE. 
 
 division of the appendages to the lemma and one of the outer glumes 
 liave been again separated into two subdivisions. The resulting 
 number of possible varieties is in consequence very large. 
 
 FERTILITY. 
 
 Barley, being a typical Hordeum, produces three single-flowered 
 spikelets at each node of the rachis. In the 6-rowed forms, all three 
 of these are fertile. In the 2-rowed only the central spikelet of each 
 three is fertile. There are four degrees of fertility, two in the 
 6-rowed and two in the 2-rowed forms. The four divisions are 
 based upon characters of the lateral florets, the central floret being 
 the same in all. The lateral florets of nonnal 6-rowed barleys are 
 completely fertile and awned or hooded. The common 2-rowed 
 barleys are characterized by sterile lateral florets, which are awnless 
 and normally rounded at the tip. In the intermediate barleys the 
 side florets are fertile, but the resulting kernels are usually small 
 and the tips are without awns. Ordinarily the lemmas are rounded, 
 but occasionally they boar bristlelike projections. In most varieties 
 of this group only part of the lateral florets ai"e fertile. The fourth 
 division is distinguished from the common 2-rowed form by a still 
 further reduction of the side florets. This reduction may be carried 
 to the point where only a single outer glume is present. Usually 
 the spikelets are represented only by the outer glumes and rachilla, 
 the floral glumes and sexual organs being entirely aborted. In some 
 strains the lemma is present, and in a very few there are traces of 
 the p'alet. Rudimentai-y ovaries and stamens are never found. 
 Barleys in which sterile ovaries, rudimentary stamens, or well- 
 developed palets appear are classed as normal 2-rowed forms. 
 
 ADHERENCE OF THE FLOWERING GLUME. 
 
 The distinction between adherent and nonadherent flowering 
 glumes is the sharpest and most easily determined of the six. It 
 separates the barleys into the hulled and naked forms. In the 
 hulled varieties the ovary grows fast to the lemma shortly before 
 maturity. In the naked sorts this union does not take place, and 
 when the spikes are thrashed the keniel thrashes free from the 
 glume, as in wheat. 
 
 OUTER GLUMES. 
 
 Each floret in barley is subtended by a pair of outer glumes. These 
 are normally narrow, lanceolate bracts, with' short, bristlelike awns. 
 In rare cases they are expanded and the length of the awn increased. 
 Those varieties with wide outer glumes have been further separated 
 by some authorities, because in some instances all six of the outer 
 glumes at a node are widened, whereas in other cases only the two 
 
THE IDENTIFTCATTOK OF VARIETIES OF BARLEY. 7 
 
 outermost of the six are so expanded. The expanded outer glume 
 is a rare variation, which may be disregarded from an agricuhui-al 
 standpoint, as no such varieties are cultivated commonly. 
 
 TERMINAL APPENDAGES OF THE LEMMA. 
 
 The lemma of either central or lateral spikelets may terminate in 
 an awn or hood, or it may be merely rounded or pointed at the tip 
 without either awn or hood. The hooded barleys usually are re- 
 ferred to in this country as beardless. Since there are true awnless 
 sorts the term awmless is here used for these rare varieties and the 
 term hooded for all varieties with hoods. The use of the term beard- 
 less, which is easily misunderstood, is thus avoided. The hooded va- 
 rieties all appear to trace their origin to the Nepal barley. In this 
 variety the awn is replaced by a trifurcate appendage, the three lobes 
 of which are a partial duplication of the three florets at a node 
 of the rachis. These monstrous florets often bear fertile stamens and 
 are said sometimes to produce seed. 
 
 In the hooded barleys two minor separations have been made. 
 The normal hood, as in the Nepal barley, is sessile. In many hybrids 
 the hood is elevated more or less on an awn. . Variations in. the small 
 awns sometimes produced by the hood also have been noted. 
 
 The aw^ns of barley may be either rough or smooth. They are 
 normally very scabrous, being much rougher than those of wheat. 
 In a few potentially valuable agronomic forms the awns are smooth 
 or slightly roughened at the tip. They are, however, entirely smooth 
 toward the base, w^here the largest teeth are found in the rough- 
 awned varieties. There are also a number of minor forms which 
 bear awns considerably shorter than the normal. In others, the awn 
 is malformed, being flattened or twisted. The difficulty of using 
 either of these latter distinctions in other than an agronomic way is 
 at once apparent, the one being a merging character and the last 
 an abnormal'ity. 
 
 COLOR. 
 
 Four color conditions have been recognized in barley varieties. In 
 the hulled varieties the distinction is based upon pigments located 
 in the lemma and such aleurone and other colors as may show 
 through the more or less translucent lemma. The naked varieties 
 are separated on pigments found in the caryopsis, disregarding en- 
 tirely the character of the lemma. In the hulled varieties the first 
 color division is that in which no pigment is present. This results 
 in a white or yellow barley. The second and third divisions, blue 
 and purple, as previously pointed out (Harlan, 1914, p. 30), prob- 
 ably are related. The blue varieties of hulled barley come from a 
 blue aleurone layer showing through the superimposed lemmas. 
 
8 BULLETIN 622, U. S. DEPARTMENT OF AGRICULTURE. 
 
 The purple colors are in the glumes themselves. The black colors 
 come from a melaninlike pigment, which in the hulled varieties 
 occurs in the lemmas. This may exist in ditl'erent degrees and has 
 been used to subdivide black barleys, although the advisability of 
 separating on degree is questionable. 
 
 In the naked varieties the colors are determined more easily. The 
 absence of pigment results in a white or yellowish grain, as in the 
 hulled. The blue colors are located in the aleurone layer. In mature 
 specimens they are unmistakable ; in immature ones the color is slight 
 and may give only a bluish cast, as it is deposited late in the develop- 
 ment of the kernel. In the Avhite varieties immaturity may result in 
 a greenish appearance which might be confused with immature blue 
 kernels. The purple color results from a blue aleurone layer beneath 
 a red pericarp. In all purple varieties at present known the color is 
 well developed except in very immature specimens and can be deter- 
 mined without difficulty. Black naked varieties with a true melanin 
 pigment are very rare. Purple naked ones are usually referred to as 
 black, although in reality they contain no black pigment and are 
 separated easily from those having the black pigment. 
 
 DENSITY. , 
 
 Density unfortunately has been used as a major distinction in the 
 classification of barley and usually has been confused with fertility. 
 This is the most unsatisfactory of all the six characters. The behavior 
 of hybrids indicates that density is determined by heritable factors, 
 however, and further information upon its behavior may increase 
 greatly its value as an agronomic character useful in the description 
 of biotypes. As may be seen in Plate I, in tj^ical forms, such as 
 Peacock, Plumage, and Hanna, representing zeocriton, erectum, and 
 nutans, respectively, the differences are marked. The intergradations 
 are so numerous and so complete that any broad application results 
 in confusion. Statements in taxonomic publications on barley indi- 
 cate that all investigators have had great difficulty in making satis- 
 factory separations. The groups have been divided into dense and lax 
 varieties. In some cases the dense varieties have been further__sub- 
 divided into dense and very dense groups. Kornicke in some of his 
 treatments has divided even the very dense into two subdivisions. 
 Such confusion is inevitable wherever separations are made upon 
 degree, and the use of density has been confined in this paper to the 
 description of subvarieties. 
 
 SCHEME OF CLASSIFICATION. 
 
 A very superficial survey of the combinations that are possible with 
 the variable factors just described is sufficient to indicate the scope 
 
Bui. 622, U. S. Dept. of Agriculture. 
 
 Plate I. 
 
Bui. 622, U. S. Dept. of Agriculture. 
 
 Plate II. 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 9 
 
 of the problem to be solved. When it is realized that a great number 
 of these forms are known and that there is no reason why all of them 
 can not be produced, or indeed may not be found already in exist- 
 ence in some part of the world, the futility of continuing the policy 
 of describing each minor variation becomes apparent. In fact, there 
 is more to be done than merely resolving not to add to the confusion. 
 Over 200 forms have been named and described. Some semblance 
 of order must be brought about in the work already published and 
 some constructive plan suggested whereby future additions may be 
 limited to variations of real importance. When the variable char- 
 acters are studied carefully with this object in view, it soon becomes 
 apparent that the factors are not all of the same value. 
 
 The fertility and the adherence or nonadherence of the lemmas are 
 major distinctions. They seldom present any difficulties. The 
 nature of the appendages of the flowering glume are major distinc- 
 tions so far as the distinctions between awns and hoods are con- 
 cerned. The presence or absence of hoods is obvious. In the sepa- 
 ration of varieties the term " awned " has been made to include awn- 
 less and all intergradations, as a complete series from awnless to fully 
 awned seems likely to exist. White and black kernels are also major 
 distinctions. White has been used to include blue and purple, because 
 of the frequently imperfect production of the latter pigments and the 
 difficulty of determining doubtful varieties. By using only these 
 four groups, the varieties are founded upon distinct and readily sepa- 
 rable characters. Each variety is then a specific, tangible group. 
 
 As lesser but still usal^le distinctions there are the awnless and 
 smooth-awned variations of the awned form, the blue and purple 
 variations of white, and the character of the outer glumes. 
 
 Besides these, a considerable number of characters have been used 
 in establishing varieties which in the light of present information 
 seem unsuited as bases for taxonomic groups. In many instances 
 they are very useful in agronomic work in the description of biotypes 
 and in the identification of farm varieties, but they are not here recog- 
 nized. Varieties which have been established upon these characters 
 will be found only in the alphabetical list of rejected forms. .These 
 characters will not be discussed individually, but will be found 
 listed in the summary below. 
 
 To summarize the variations, the three grades of distinction are as 
 follows : 
 
 Major distinctions useful in estaUishing species and varieties: 
 Spikes 6-rowed, intermediate. 2-rowed. and deficient. 
 Kernels hulled and naked. 
 
 Lemmas awned (including awnless) and hooded. 
 Kernels while (Including blue and purple) and black. 
 14681°— 18— Bull. 622 2 
 
10 BULLETIN 622, U. S. DEPARTMENT OP AGRICULTURE. 
 
 Minor distinctions xiseful in describing subvarieties: 
 
 Outer glumes wide and narrow. 
 
 Lemmas awnless and smooth awned as variations of awned. 
 
 Kernels blue and purple as variations of white. 
 Minor distinctions ivJiich are best used in describing agronomic biotypes (va- 
 rieties founded on these are here disregarded except in the alphabetical list) : 
 
 Only two outermost glumes expanded a§ a variation of wide outer 
 glumes. 
 
 Elevation of the hood on a short awn. 
 
 Small awns arising fj-om the hood. 
 
 Flattened or twisted malformations of the awn. 
 
 Short awns, except as noted in awnless. 
 
 Character of the hairs of the rachilla. 
 
 Scabrousness of the nerves of the lemma. 
 
 Proliferation of the spike. 
 
 THE SPECIES OF CULTIVATED BARLEY. 
 
 The species are of necessity based on fertility. This is predeter- 
 mined essentially by the work already published, fertility having 
 been used as a basis of separation since the earliest observations on 
 barley. 
 
 There is no such unity of opinion in fixing the number of species. 
 Some favor placing all cultivated barleys under a single species, as 
 did Jessen (18.55) . To the writer, on the other hand, the group seems 
 too broad to be so united. Clearness is better served by making the 
 species a smaller unit. Certainly no group of wild plants of such 
 variation is united under a single species, and there is abundant evi- 
 dence in the behavior of hybrids that at least tAvo parents were in- 
 volved in the production of the forms now domesticated. If fertility 
 is to be subdivided there are three bases upon which it can be accom- 
 plished. Many of the earlier writers recognize only two divisions, 
 2 rowed and 6 rowed. Among the modern investigators Kegel takes 
 this view. This has the disadvantage of throwing the hybrid inter- 
 mediate forms with the 6-rowed, Avhen physiologically th3 indications 
 are that they are nearer the 2-rowed forms. The only Avay to avoid 
 this complication is to recognize the hyl)rid species intermedium of 
 Kornicke. We then have three grades of fertility. There are actu- 
 ally. However, four conditions. In one group of Abyssinian 2-rowed 
 barley the lateral spikelets are rudimentary. Although this distinc- 
 tion is not as sharp as the others and needs a larger collection of 
 Abyssinian material to determine its status clearly, there is no justifi- 
 cation at present for rejecting the character. If three conditions are 
 recognized, the fourth should be, which means the acceptance of the 
 division ileflcieTis as equal in value to distichon and vulyar'e, as sug- 
 gested by Voss (1885), 
 
 : I 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 
 
 11 
 
 The four species, vulgare^ intermediwm^ distichon^ and deficiens^ 
 shown in Plate II, seem best to represent the differences as they exist. 
 It is not to be assumed that this is the only method of separation 
 which might be made on the basis of fertility. Genetically the pointed 
 or rounded nature of the lateral floret may be correlated with the true 
 relationship of the varieties, but it would be practically impossible to 
 use this distinction in the deflciens group. Neither does it fit in with 
 vrork already done. On the other hand, the species founded upon fer- 
 tility alone require little modification of existing schemes. As has 
 been noted previously, many taxonomists in the past have combined 
 and even confused fertility with density. The work of Kornicke 
 well illustrates this point. As Kornicke is the most widely known of 
 the investigators who have combined the two characters, his scheme 
 is represented graphically in Table I. 
 
 Table I. — Scheme of classification of barley founded upon both fertility and density. 
 [Terms in italic represent Korniclie's major groups.] 
 
 polystichum . . ^ 
 
 II. vuigare. 
 
 normal 6-rowed \ 
 
 intermedium. 
 
 distichum. 
 
 (normal 2-rowed 
 deficient 2-rowed. 
 
 (hexastichum . 
 
 tetrastichum. 
 
 dense. 
 
 lax. 
 
 dense 
 
 lax. 
 
 very dense, 
 dense. 
 
 very dense, 
 dense. 
 
 It will be noted that Kornicke's major groups have very little 
 relation to each other. Beaven (1902) remedied this defect to some 
 extent by carrying over zeocriton to designate the dense normal 
 2-rowed, distichon. to represent the lax, and decipiens to designate 
 the deficient 2-rowed barley. His grouping, however, was not on 
 equal separations, in that the mtermedium and decipiens were sepa- 
 rated further into dense and lax, which separations are parallel 
 with his zeocrito?i, distichon, vuigare {tetrastichutii Kcke.), and 
 hexastichon. Although the system of Beaven was an improvement 
 in a way, it still maintained the objectionable principle of com- 
 bining the characters of density and fertility. 
 
 When the present work was begun it was thought that it would 
 be almost impossible to maintain these well-established distinctions. 
 However, by eliminating the density factor and retaining only the 
 question of fertility, the four species already mentioned were ob- 
 tained. This scheme is graphically represented in Table II. 
 
12 BULLETIN- 622^ U. S. DEPARTMENT OF AGRICULTUEE. 
 
 Table II. — Scheme of classification of barley founded upon fertility, eliminating density . 
 
 Genus. 
 
 Section. 
 
 Subsection. 
 
 Species. 
 
 
 
 
 viilgare. 
 
 TTo'^'lenTn , , , 
 
 
 
 
 distichon ... 
 
 fdistichon. 
 
 
 
 Ideflciens. 
 
 KEY TO THE SPECIES. 
 
 The meaning of the graphic representation is made somewhat 
 clearer by consulting the key to the species. It will be noted that the 
 absence of appendages on the lateral florets is used to separate the 
 species intei'mediiiTn. This distinction is in reality one of fertility, 
 the most obvious indication of which is the absence of appendages on 
 the lemma. These lateral florets are probably not comparable to the 
 'lateral florets of vulgare but to the lateral florets of distichon^ differ- 
 ing from the latter in having become fertile. 
 
 Key to the species. 
 
 All spikelets fertile (6-rowed barley). 
 
 Lemmas of all florets awned or hooded vulgare L. 
 
 Lemmas of lateral florets bearing neither awns nor hoods. 
 
 intermedium Kcke. 
 Only the central spikelets fertile (2-rowed barley). 
 
 Lateral spikelets consisting of outer glumes, lemma, palet, rachilla, and 
 
 iisually rudiments of the sexual organs distichonli. 
 
 Lateral spikelets reduced, usually to only the outer glumes and rachilla, 
 rarely more than one flowering glume present, and never rudiments of 
 sexual organs deficiens Steud. 
 
 Of these species the first three present no nomenclatural difficul- 
 ties. Vulgare and distichon trace direct to Linnseus (1753), and in- 
 termedium to Kornicke (1882, p. 125). In the fourth there is more 
 question of priority. According to Kornicke and Werner (1885), 
 Steudel described deficiens in 1842. Aj)parently there was no pub- 
 lished description, the identification being only the name written on 
 a herbarium sheet of Schimper's Abyssinian collection. The name 
 first applied appears to have been decipiens and not deficiens. In 
 1854 (p. 351) Steudel gives a very complete description of deflcie^is 
 as a species. So far as the v,'riter can learn, this is the first time the 
 name was used in print. In May, 1842, Seringe (p. 194) in addi- 
 tions to the genus Hordeum describes all the common forms of defi- 
 cient barley under the variety abyssinicum. 
 
 In the key the only question arises in the separation of the defi- 
 cient 2-rowed from the normal 2-rowed barleys. Deficient types are 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 13 
 
 uncommon, and deficient barleys which show intergradations toward 
 the normal 2-rowed are rare indeed. 
 
 In the 6-rowed barleys all awnless forms are thrown into inter- 
 medium. The awnless character is most probably of hybrid origin, 
 and in all 6-rowed awnless varieties now known there is a tendency 
 in some strains to produce short awns on the central spikelets when 
 grown under especially favorable conditions, indicating a direct rela- 
 tionship with intermedium. It may be found necessary to include 
 awnless sorts under Hordeum^ vulgare as well, but at present it seems 
 better to list these forms with the intermedium/. 
 
 Of the varieties and subvarieties which follow, a large number are 
 of hybrid origin. The species intermedium^ probably consists entirely 
 of hybrid varieties. In the beginning it was attempted to separate 
 the known hybrid varieties from those occurring naturall5\ How- 
 ever, there seems no good reason for such a distinction, for many of 
 the varieties which are not known to be hybrid probably have arisen 
 from accidental crossing. 
 
 For example, the variety horsfordianum was named for a Mr. 
 Horsford in Vermont, who crossed a Nepal (6-rowed hooded naked) 
 on a 6-rowed bearded hulled and obtained a 6-rowed hooded hulled. 
 This variety is grown extensively in the United States and is abso- 
 lutely constant. It is inconceivable that all barley of this descrip- 
 tion in this country and elsewhere came from Mr. Horsford's cross. 
 The Nepal has been grown in India alongside of hulled varieties for 
 centuries, and the cross must have occurred time and again naturally, 
 despite the fact that barley is one of the most closely fertilized of 
 plants. It is a strange coincidence that the only natural hybrid that 
 has occurred in the nursery in the six years of this investigation was 
 between the Nepal and a 6-rowed bearded hulled variety, from the 
 progeny of which a Horsford type has been isolated. 
 
 In describing varieties, fertility having been used as a specific dis- 
 tinction, there remain hulled or naked kernels, awned (including 
 awnless) or hooded lemmas in the central spikelet, and white (includ- 
 ing blue and purple) or black color as major distinctions. The first 
 two of these characters, with the variation in width of the outer 
 glumes later spoken of in the discussion of subvarieties, are shown 
 in Plate III. The regularity of the gradation in difi'erences be- 
 tween the varieties in each group is sufficient to excite the suspi- 
 cion of the taxonomist, because such uniformity is not common in 
 nature. Ordinarily, variations do not occur in a closely graded series. 
 Neither did they in barley at first, but continued crossing, natural and 
 artificial, has slowly filled the gaps. 
 
 Hordeum vulgare trifurcatum., for example, at first stood off 
 clearly as the trifurcate naked 6-rowed barley. Then horsfordianwm 
 was produced and there were two trifurcate 6-rowed sorts, one hulled 
 
14 BULLETIN 022, U. S. DEPARTMENT OF AGRTCULTUBE. 
 
 and the other naked. Later, the trifurcate character was trans- 
 ferred to many forms, until H. v. trifurcatum is noteAvorthy only as 
 the parent form of trifurcate barleys. This illustrates the vital dif- 
 ference between the treatment of a group with only a few representa- 
 tives and one with many. The greater the number of forms, the 
 fewer are the characters that separate them. 
 
 KEY TO THE VARIETIES. 
 
 Following is the key to the varieties occurring under the four spe- 
 cies of barley : 
 
 Hordeum vulgare. Barleys with three fertile spikelets at each node, the lemmas 
 of both central and lateral florets bearing awns or hoods. 
 Kernels hulled. 
 
 Lemmas awned. 
 
 Kernels white, bine, or purple 1. pallidum. 
 
 Kernels blaok 2. nigrum. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or purple 3. Jiorsfordianum. 
 
 Kernels black 4. atriim. 
 
 Kernels naked. 
 
 Lemmas awned. 
 
 Kernels white, blue, or purple 5. coeleste. 
 
 Kernels black -1 6. duplinigrum. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or purple 7. trifurcatum. 
 
 Kernels black 8. aethiops. 
 
 Hordeum intermedium. Barleys in which the lateral 
 florets are fertile but awnless. 
 Kernels hulled. 
 
 Lemma of central floret awned or awnless. 
 
 Kernels white, blue, or purple 9. haxtoni. 
 
 Kernels black 10. mortoni. 
 
 Lemma of central floret hooded. 
 
 Kernels white, blue, or purple 11. subcornutum. 
 
 Kernels black 12. atricornuttim. 
 
 Kernels naked. 
 
 Lemma of central floret awned or awnless. 
 
 Kernels white, blue, or purple 13. nudihaxtoni. 
 
 Kernels black . 14. nudimortoni. 
 
 Lemma of central floret hooded. 
 
 Kernels white, blue, or purple 15. cornutum,. 
 
 Kernels black 16. subaethiops. 
 
 Hordeum distichon. Barleys in which the lateral florets 
 are present but sterile. 
 Kernels hulled. 
 
 Lemmas awned or awnless. 
 
 Kernels white, blue, or purple 17. pahnella. 
 
 Kernels black 18. nigricans. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or purple 19. angustispicatum. 
 
 Kernels black 20. rimpauL 
 
THE IDENTIFICATION" OF VARIETIES OF BARLEY. 15 
 
 Hordeum disHclion — Continued. 
 Kernels naked. 
 
 Lemmas awned or avvnless. 
 
 Kernels white, blue, or purple 21. nudmn. 
 
 Kernels black 1 22. nigrinudum. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or purple 23. laxuni. 
 
 Kernels black 24. nigrilawum. 
 
 Hordeum deficiens. Barleys in which the lateral florets 
 are not only sterile but rudimentary. 
 Kernels hulled. 
 
 Lemmas awned or awnless. 
 
 Keiliels white, blue, or purple 25. deficiens. 
 
 Kernels black 26. steudelii. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or pui'ple 27. triceros. 
 
 Kernels black 28. tridax. 
 
 Kernels naked. 
 
 Lemmas awned or awnless. 
 
 Kernels white, blue, or purple 29. nudideflciens. 
 
 Kernels black 30. decorticatum. 
 
 Lemmas hooded. 
 
 Kernels white, blue, or purple 31. sublaxum. 
 
 Kernels black 32. gymnospermum. 
 
 The 32 varieties described above are thought to constitute the 
 major variations in barley. It is possible that a group of Abys- 
 sinian barleys may later be added to the intermediate forms, but it 
 is hoped that this may be avoided. In the list of subvarieties which 
 follows there have been no additions, although many new sorts are 
 available. It is thought best not to add to this list of named sorts, 
 as the large number of names is already confusing. The list of sub- 
 varieties is made up entirely of forms that have been published as 
 varieties, but which are little more than variations of an established 
 type. As these names have been used and as the distinctions have 
 some foundation, even though often a fragile one, it is necessary to 
 indicate the group each was intended to describe. It can not be too 
 strongly recommended, however, that additions be made to the list 
 of subvarieties only when the value of the addition is above question. 
 At the present time the writer has in his possession blue, purple, 
 and smooth-awned variations in a large number of new combina- 
 tions. A dense form of tonsmn has been received recently from 
 Japan. Many dense forms of deficient barleys have been isolated 
 from Abyssinian barley, with a complete series of colors. The addi- 
 tion of these to the named subvarieties seems to offer no advantages, 
 and when they are described it will be only in a list of agronomic 
 varieties which is expected to supplement the present publication. 
 
16 BULLETIN 022, U. S. DEPARTMENT OF AORTCULTTTKE. 
 
 KEY TO THE SUBVARIETIES. 
 
 1. Hordexmi vulgar e pallidum Sei'inge (1841, p. 346). 
 
 Outer glumes narrow. 
 KerneLs white. 
 Awns rough. 
 
 Spike narrow, lax, nodding typka. 
 
 Spike wide, dense, the edges parallel ; awns not widely spread- 
 ing parallelum Kornicke (as var., 1882, p. 166). 
 
 Spike wide, very dense, pyramidal, awns widely spreading. 
 pyramidatum Kornicke (as var., 1882, p. 164). 
 Awns smooth. 
 
 Spike narrow, lax, nodding. 
 
 rikotense Kegel (as var., 1908, p. 74). 
 Kernels bluish. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 coerulescens Seringe (as var., 1841, p. 347). 
 Kernels purple. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 sulwiolaceum Kra-nicke (as var., 1895, p. 9). 
 Outer glumes wide. 
 Kei'uels white. 
 Awns rough. 
 
 Spike narroVv% lax, nodding. 
 
 latiglumatum Kornicke (as var., 1895, p. 9). 
 Spike wide, dense, erect. 
 
 eurylepis, Kornicke (as var., 1882, p. 167). 
 
 2. Hordenm vulgare nigrum Willdenow (as sp.. 1809, p. 1037). 
 
 Outer glumes narrow. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, erect. 
 
 sehimperianum Kornicke (as var., 1882, p. 165). 
 Awns smooth. 
 
 Spike narrow, lax, nodding. 
 
 leiorrhynchum Kornicke (as var., 1882, p. 178). 
 Outer glumes wide. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 atrospicatum Kornicke (as var., 1895, p. 9). 
 Spike wide, dense, erect platylepis Kornicke (as var., 1895, p. 9). 
 
 3. Hordeum vulgare horsfordianum Wittmack (1884). 
 
 Outer glumes narrow. 
 Kernels white. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, erect. 
 
 Jiexasticofurcatum K. H. in Beaven (as var., 1902, p. 577). 
 
 4. Hordeum. vulgare atrum Kornicke (1895, p. 9). 
 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding >^_-. typica. 
 
 Spike wide, dense, erect. 
 
 densifurcatum K. H. in Beaven (as var., 1902, p. 577). 
 
THE TDENTTFTCATTON OF! VARIETIES OF BARLEY. 17 
 
 5. Hordeum rxilgare coolest e Linnaeus (as sp., 1753, p. 85). 
 
 Outer glumes narrow. 
 Kernels white. 
 Awns rough. 
 
 Spilie narrow, lax, nodding typica. 
 
 Spike wide, dense, the edges parallel, awns not widely 
 
 spreading revellatum Koi-nicke (as var., 1882, p. 167). 
 
 Spike wide, very dense, pyramidal, awns widely spreading. 
 
 nudipyramidntum Kornicke (as var., 1895, p. 9). 
 Kernels blue. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 himalayense Rittig (as var., 1822, according to Roemer 
 and Schult(?s, 1824, p. 481). 
 Kernels purple. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 violaceum Kornicke (as var., 1882, p. 183). 
 Outer glumes wide. 
 Kernels white. 
 i^.wns rough. 
 
 Spike narrow, lax, nodding. 
 
 sublafiglumatmn Kornicke (as var., 1908, p. 425). 
 
 6. HoriLeum vulgare dupUnigrum Kornicke (1895, p. 9; modified, 1908, p. 424). 
 
 Outer glumes narrow. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 7. Hordeum vulgare tnfnrcatum Schlechtend£hl (1837, p. 543). 
 
 Outer glumes narrow. 
 Kernels white. 
 
 Spike uari'ow, lax, nodding typica. 
 
 8. Hordeum vulgare aethiops Kornicke (1895, p. 10). 
 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding typica. 
 
 9. Hordeum intermedium haxtom Kornicke (1882, p. 185). 
 
 Oute** glumes narrow. 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, the edges parallel ; awns not widely spread- 
 ing transiens Kornicke (as var., 1882, p. 185). 
 
 Spikes wide, very dense, pyramidal, awns widely spreading. 
 
 pavoninum Kornicke (as var., 1908, p. 429). 
 Lemma of central floret awnless. 
 
 tonsum Kornicke (as var., 1908, p. 426). 
 
 10. Hordeum intermeditun mortond Kornicke (1908. p. 429). 
 (^uter glumes narrow. 
 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Lemma of central floret awnless. 
 
 nigritonsum Kornicke (as var., 1908, p. 426). 
 
IS BULLETIN 622^ IT. S. DEPARTMENT OF AGRTCULTITRE. 
 
 11. Hordeum intermedium snhcornntmn Kornicke (1908, p. 425). 
 \ Outer glumes naiTow. 
 
 Kernels white. 
 
 Spike narrow, lax, nodding •_ typica. 
 
 Spike wide, dense, erect. 
 
 anomalum Kornicke (as var., 1895, p. 10; and 1908, p. 430). 
 
 12. Hordeum. intermedium atricornutum Kornicke (1908, p. 425). 
 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding typica. 
 
 13. Hordeum intermedium nudihaxtoni Kornicke (1908, p. 429). 
 Outer glumes narrow. 
 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, erect. 
 
 nuditransiens Kornicke (as var., 1908, p. 430). 
 Lemma of central floret awnless. 
 
 nuditonsum Kornicke (as var., 1908, p. 426). 
 
 14. Hordeum intermedium nudimortoni var. novo. This variety was selected 
 from the progeny of a hybrid of haxtoni and nigrinudum. It is constant, and 
 with^;he other new forms described later is included here in order that the 
 list of principal varieties may be complete. It is a variety of intermedium 
 with black, naked kernels, lemmas of the central florets awned, outer glumes 
 narrow, and spike lax and nodding. 
 
 15. Hordeum intermedium cornutum Schrader (1838, p. 471). 
 Outer glumes narrow. 
 
 Kernels white. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, erect. 
 
 gymnanomalum Kornicke (as var., 1908, p. 430). 
 
 16. Hordeum intermedium subaethiops Kornicke (1908, p. 425). 
 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding typica. 
 
 17. Hordeum distichon palmella var. novo. In the common 2-rowed barleys 
 there has apparently been no name used in recent years to include zeocriton, 
 erectum, and nutans. Each of these has such a detiuite and specific use as a 
 subvarietal name that it can hardly be used to include the others. Jean des 
 Moulins in 1615, in the French edition of the work of Dalechamps (p. 333), 
 divided the barleys into two species, polystichon and distichon. The latter he 
 called pomole. Olivier de Serres, writing the same year (p. 99), used the 
 terms paumes and paumoules for the same barleys. The pomole of that date 
 was nearly identical with the group here designated palmella. Pomole, with 
 various spellings, as paumoule, pamelle, etc.. is still applied popularly to the 
 connuon 2-rowed barleys in France. The name palmella, is here used in 
 preference, as the Latin equivalent of palm, or little palm, doubtless referring 
 to the appearance of the spike. 
 
 Outer glumes narrow. 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 nutans Schuebler (as var., 1818, p. 86). 
 Spike wide, dense, the edges parallel ; awns not widely 
 
 spreading erectum Schuebler (as var.. 1818, p. 36). 
 
 Spikes wide, veiy dense, awns widely spreading. 
 
 seocriton Linnaeus (as sp., 1753, p. 85). 
 
THE IDENTIFICATION OP VARIETIES OF BARLEY. 19 
 
 17. Hwdeum distiehon palmelhi — Continued. 
 
 Outer glumes narrow — Continued. 
 Kernels white — Continued. 
 Awns smooth. 
 
 Spike n;irrow, lax, nodding. 
 
 riyens K. H. in Beaven (as var.. 1902, p. .578). 
 
 Awns wanting inerme Kornicke (as var.. 1895, p. 8). 
 
 Kernels hluish. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 canescens K. H. In Beaven (as var., 1902. p. .578). 
 Awns smooth. 
 
 Spike narrow, lax, nodding. 
 
 medicum Kornloke (as var., 1882, p. 195). 
 Kernels purple. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 hijpianthimmi Koruicke (as var.. 1895. p. 10). 
 Outer glumes wide. 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 diibium Kornicke (as var., 1908, p. 431). 
 Spike wide, dense, erect. 
 
 macrolysis K. H. in Beaven (as var., 1902, p. 578). 
 
 18. Hordeiim distiehon nif/ricans Seringe (1842, p. 3.57). 
 
 Outer glumes narrow. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, the edges parallel, awns not widel.v spreading. 
 
 contractum Kornicke (as var., 1882, p. 198). 
 Spike wide, dense, erect, awns widely spreading. 
 
 mekmocrithum Kornicke (as var., 1882. p. 2<X)). 
 Awns smooth. 
 
 Spike nai'row, lax, nodding. 
 
 pcrHiciim Kornicke (as var., 1882, p. 19G). 
 Awns wanting. 
 
 decussatum Kurnicke (as var., 1895. p. 8). 
 Outei- glumes wide. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 brmmii Kornicke (as var., 1882. p. 202). 
 Spike wide, dense, erect. 
 
 mixtum K. H. in Beaven (as var., 1902, p. 578). 
 
 19. Hordcum distiehon anfiuHtispicatum Kornicke (1895, p. 11). 
 
 Outer glumes narrow. 
 Kernels white. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, the edges parallel . awns not widely .spreading. 
 
 latispicatum Kornicke (as var., 1895, p. 11). 
 Spikes wide, very dense, awns widely spreading. 
 
 furvutozeocriton K. H. in Beaven (as var., 1902, p. 578).. 
 
20 BULLETIN 622, U. S. DEPARTMENT OF AGEIGULTUEE. 
 
 19. Hordeum distichon angust is pica turn — Continued. 
 ^ Outer glumes narrow — Continued. 
 
 Kernels purple. 
 
 Spike narrow, lax, nodding. 
 
 koernickei K. H. in Beaven (as var., 1902, p. 579). 
 
 20. Hordeum distichon rimpaui Wittm. (Kornieke, 1895, p. 11). 
 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding typica. 
 
 21. Hordeum disticJwn nudum Linnaeus (1753, p. 85). 
 
 Outer glumes narrow. 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, the edges parallel ; awns not widely spread- 
 ing iieogenes Kornieke (as var., 1895, p. 10). 
 
 Spike wide, very dense, awns widely spreading. 
 
 gymnocritlmm Kornieke (as var., 1895, p. 10). 
 
 Awns wanting duploalbum Kornieke (as var., 1895, p. 8). 
 
 Kernels bluish. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 7-ossii Koi'nicke (as var.. 1895, p. 10). 
 Kernels purple. 
 Awns rough. 
 
 Spike narrow, lax, nodcUng. 
 
 iafttliMum Kornieke (as var., 1895, p. 10). 
 Outer glumes wide. 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 nudidubium Kornieke (as var., 1908, p. 431). 
 
 22. Hordeum distichon nigrinudum var. novo. This form was isolated in 1909 
 from an importation of Abyssinian barleys. Two naked seeds were found, 
 which were so black that they appeared to have been charred. They proved 
 viable, however, and have since produced coal-black seeds. In other respects 
 the variety corresponds to nudum. 
 
 Outer glumes narrow. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Awns wanting duploatriuii Kornieke (as var., 1895, p. 8). 
 
 23. Hordeum distichon laxum Kornieke (1895, p. 7). 
 
 Outer glumes narrow. 
 Kernels white. 
 
 Spike narrow, lax, nodding typica. 
 
 Spike wide, dense, erect densiim Kornieke (as var., 1895, p. 11). 
 
 24. Hordeum distichon nigrilaxum var. novo. This variety was produced from 
 a cross of horsfordianum and nigrinudum-. It is a 2-rowed, liooded barley of 
 the species distichon, with naked black seeds, outer glixmes narrow, spike 
 narrow, lax, nodding. 
 
 25. Hordeum deflciens deflciens Steudel (1854, p. 351). 
 
 Outer glumes narrow 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 21 
 
 25. Hordeum deflciens deficiens — Continued. 
 Outer glumes wide. 
 
 Kernels white. 
 Awns x*ough. 
 
 Spike narrow, lax. nodding. 
 
 rehmii Kornicke (as var., 1895, p. 10). 
 
 Spike wide, dense, erect abyssinicum Seringe (as var.. 1842, 
 
 p. 194 ; modified, Kornicke, 1882, 
 p. 202). 
 
 Awns wanting subinerme Kornicke (as var.. 1895, p. 8). 
 
 Kernels bluish. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 pseudoabys-miicnni Kornicke (as var., 1908, p. 432). 
 
 26. Hordeum deflciens steudelii Kornicke (1882, p. 206). 
 Outer, glumes narrow. • 
 
 Awns r»Bgh. 
 
 Spike narrow, lax, nodding typica. 
 
 Awns smooth. 
 
 Spike narrow, lax, nodding. 
 
 subglabrion K. H. in Beaven (as var., 1902, p. 579). 
 
 Awns wanting subdecussatiun Kornicke (as var., 1895. p. 8). 
 
 Outer glumes wide. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 macrjolepis A. Br., (as var., 1848, according to Kornicke, 1885, 
 Bd. 1, p. 185). 
 Awns smooth. 
 
 Spike narrow, lax, nodding. 
 
 Ici'omacrolepis Kegel (as var., 1908, p. 78). 
 
 27. Hordeum deflciens tricolor Korniclve (1895, p. 11.) 
 
 Outer glumes narrow. 
 Kernels white. 
 
 Spike narrow, lax, nodding typica. 
 
 28. Hordeum deflciens tridax Kornicke (1895, p. 11). 
 
 Outer glumes narrow. 
 
 Spike nari'ow, lax, nodding typica. 
 
 29. Hordeum deflciens nudideflcicns Kornicke (1895, p. 11). 
 Outer glumes narrow. 
 
 Kernels white. 
 Awns rough. 
 
 Spike narrow, lax, nodding ^typica. 
 
 Awns wanting subduplialbum Kornicke (as var., 1908, p. 4.S4). 
 
 Kernels purple. 
 Awns rough. 
 
 Spike narrow, lax, nodding. 
 
 vimscens K. H. in Beaven (as var., 1902, p. .579). 
 
 30. Hordeum deflciens decorticatum Kornicke (1895, p. 11). 
 
 Outer glumes narrow. 
 Awns rough. 
 
 Spike narrow, lax, nodding typica. 
 
 Awns wanting subdupliatrum Kornicke (as var.. 1908, p. 434). 
 
22 BULLETIN 622, U. S. DEPARTMENT OF AGRICULTURE. 
 
 31. Hordtnm deficicnft siibla.rinn Kornicke (1908, p. 433). 
 ^ Outer glumes narrow. 
 Kernels white. 
 
 Spike narrow, lax, nodding tijpica. 
 
 .32. Hordevm deflciens gymnospermum Kornicke (1895, p. 11). 
 Outer glumes narrow. 
 
 Spike narrow, lax, nodding typ'wa. 
 
 REJECTED SPECIES, SUBSPECIES. AND VARIETIES. 
 
 In the analysis of the relative value of the variable characters of 
 barley, a number of variations were regarded as of too minor a nature 
 to be used even in the description of named subvarieties. These in- 
 cluded the elevation of the hood on a short awn, awns produced 
 on the hood itself, malformed awns, short awns, the nature of the 
 hairs on the rachilla, the toothing of the nerves of the lemma, and the 
 widening of only the two outermost glumes at a node. Varieties 
 established upon these characters are not recognized in the key. Inas- 
 much as the names often appear in papers on barley, a statement of 
 the nature of the variation is necessary for reference use. For this 
 reason an alphabetical list of discarded species and varieties has been 
 prepared. A few groups founded on other bases have been included. 
 The most important of these is probably that of compound spikes. 
 The inclusion of compound spikes as a recognized character would 
 simply double the number of varieties. In barley, proliferation of 
 spikes is common, but in most strains it is not inherited. In others, 
 while the tendency is transmitted, it is inherited imperfectly. Even 
 if it were perfectly heritable its use would offer little of advantage. 
 The list also contains various synonyms which have been published 
 from time to time. In a few instances names occur both in the key 
 and in the list of rejected forms. In these cases the names have 
 been used in two or more ways and in the misapplied use appear 
 here. Where the form is compared with one in the key, it bears the 
 key number of the recognized variety. 
 
 ALPHABETICAL LIST OF REJECTED SPECIES, StJBSPECIES, AND VARIETIES. 
 
 ahyssinicion Seringe (1842. p. 194, as. var.), as originally described equal to 
 
 the species deflciens. 
 aegiceras Royle (1839, p. 418), synonym for H. v. trifurcatum (7). 
 aethioplciim Alefeld (1866, p. 343), synonym for H. distichon nigrkuns (18). 
 alhidum Kornicke (1873, p. 4), synonym for H. v. pallidum (1). 
 angustissimum Kornicke (1908, p. 432, as var.), synonym for H. distichon 
 
 laxum (23). 
 atratutn K. H. in Beaven (1902, p. ,597, as var.), synonym for H. deflciens 
 
 steudelii (26). 
 atterbergianvm Kegel (1908, p. 77. as var.), synonym for H. deflciens steudelii 
 
 subglabrum (26). 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 23 
 
 atterherffil Kornicke (1895, p. 10, as var.), H. distichon palmella nutans (17), 
 
 with lateral florets enlarged and pointed. 
 brachytheritm Kornicke (1882, p. 164, as var.), short-awned form of H. r. 
 
 pallidum pyramidatum (1). 
 brackyura Alefeld (1866, p. 340), very dense form of H. i\ pallidum pyramida- 
 tum (1). 
 beijerinckii Kornicke (1908. p. 431, as var.), H. distichon palmella macrolysis 
 
 (17), with only the two outermost glumes expanded. 
 coelestoides Seringe (1841, p. 358), sjoionym for H. distichon nudum (21). 
 commune Atterberg (1899, p. 7), used as a subspecies to designate all barleys 
 
 with narrow glumes and awned central florets. 
 compactum Kornicke (1908, p. 424, as var.), synonym for H. v. horsfordianum 
 
 hexasticofurcatum (3 ) . 
 complanatum K. H. in Beaven (1902, p. 577, as var.), synonym for H. i. sub- 
 
 cornutum anomalum (11). 
 compositum Kornicke (1882, p. 206, as vai\), compound form of H. distichon 
 
 palmella nutans (17). 
 crispicapillum Kornicke (1895, p. 10, as var.), compound form of H. v. coeleste 
 
 (5). 
 crispum Kornicke (1895, p. 4, as var.), compound form of H. v. pallidum, (1). 
 cucullatum Kornicke (1882, p. 179, as var.), a malformation of H. v. horsfordi- 
 anum (3). 
 denstim Seringe (1841, p. 345 and 357), used for subvarieties under both hex- 
 
 astichon and distichon. 
 densum Voss (1885, p. 280), used to include all dense, narrow-glumed, deficient 
 
 barleys. 
 eingens K. H. in Beaven (1902, p. 579, as var.), synonym for H. distichon rim- 
 
 paiii (20). 
 erectonudum K. H. in Beaven (1902, p. 578, as var.), synonym for H. distichon 
 
 nudum neogenes (21). 
 falsum Atterberg (1899, p. 11), used to designate all varieties with horseshoe- 
 shaped depression at base of grain. 
 flaccidum. Voss (1885, p. 279, as var.), included lax forms of H. v. coeleste (5). 
 furcatnm. Atterberg (1899. p. 7), used as subspecies, including all hooded forms 
 
 with linear outer glumes. 
 genuinnm Alefeld (1866, p. 340), synonym for H. vulgare, used as H. v. genu- 
 
 inum. 
 genuinum Eriksson (1899, p. 2). a lax subdivision of H. distichon palmella 
 
 erectum (17). 
 gracilius Kornicke (1882, p. 167, as var.), synonym for H. v. nigrum scltimpci-i- 
 
 anum (2). 
 Jieterolepis Kornicke (1882, p. 202, as var.), H. distichon palmella macrolysis 
 
 (17), with only the two outei'most glumes expanded. 
 hcuzei Kornicke (1882, p. 170, as var.), H. r. pallidum (1), with malformed 
 
 awns approaching hoods. 
 hcxastichum Linmipus (1753. p. 85, as sp.), all dense forms of H. rulyarc. 
 hibermim Heuze (1872, p. 454), Vvinter forms of //. r. pallidum pyramidatum. 
 imberbe Lamarck and Candolle (1815, p. 93). a form of H. distichan palmella 
 
 erectum (17) with deciduous awns. 
 
24 BULLETIN 622, U. S. DEPARTMENT OF AGEICULTUBE. 
 
 inaequale Voss (1885, p. 278), group term to include all lax vulgare. 
 
 inerme Atterberg (1899, p. 7), used as subspecies Including all awnless varieties. 
 
 krausiamim Wittmack (1885, p. 1), compound form of H. disHchon palmella 
 
 erectum (17), with some naked grains. 
 Jaxiftircatum K. H. in Beaven (1902, p. 578, as var.), synonj'm for H. v. atrum 
 
 (4). 
 laxum Seringe (1841, p. 344 and 356), used to designate lax varieties under 
 
 both Jiexastichon and disticJion. 
 laxum Voss (1885, p. 281), Including all lax deficient barleys with narrow 
 
 glumes. 
 macrolepis Atterberg (1899, p. 7), used as subspecies, including varieties with 
 
 wide outer glumes on the central spikelet. 
 macroteron Alefeld (1866, p. 840), less dense forms of H. v. pallidum pyrami- 
 
 datum. (1). 
 inmistrosum K. H. in Beaven (1902, p. 579, as var.), synonym for H. deficiens 
 
 gymnospermum (32). 
 muticum Hoffmann (1877, p. 272), probably deciduous H. distichon palmella 
 
 (17). 
 muticum Atterberg (1899, p. 8), as subspecies, including all varieties with large 
 
 flowering glumes in lateral spikelets, whether fertile or infertile. 
 nigrescens Kornicke (1882, p. 195, as var.), a brown form of H. distichon nigri- 
 cans (18). 
 nudiramosum K. H. in Beaven (1902, p. 578, as var.), compound form of H. v. 
 
 coeleste (5). 
 parvihamatuni K. H. in Beaven (1902, p. 579, as var.), short-awned form of 
 
 H. disticJion angustispicatum (19). 
 patens Eriksson (1889, p. 2), dense subdivision of II. distichon palmella 
 
 erectum (17). 
 platylepis Voss (1885, p. 281), included all dense, wide-glumed deficiens barleys. 
 polystichon Haller (1776, p. 5), synonym for tctrastichum Kornicke, all lax 
 
 vulgare. 
 polystichon Doll (1857, p. 119), all 6-ro\ved barleys. 
 pseudotrifurcatum Langsdorff (1860, p. 9). a form of H. v. trifurcatum (7) 
 
 carrying a short awn. 
 ramosum Seringe (1841, p. 358), a compound distichon. 
 ramosum Hochstetter (1848, p. 147), a compound form of H. deficiens (25). 
 ramulosum K. H. in Beaven (1902, p. 579, as var.), a compound form of H. 
 
 distichon nudum (21). 
 recens Kornicke (1882, p. 167, as var.), only two outermost glumes expanded, 
 
 otherwise as H. v. pallidum eurylepis (1). 
 rectum Voss (1885, p. 278), dense forms of H. r. coeleste (5). 
 rostratum Atterberg (1899, p. 9), as muticum, except that the awnless spikelets 
 
 of the former bear hairlike awns. 
 sativum Jessen (1855), used as a single species to include all cultivated barleys. 
 scMveinfurthii Kornicke (1908, p. 420, as var.). synonym for H. distichon 
 
 nigricans (18). 
 serratum K. H. in Beaven (1902, p. 579, as var.), synonym for H. deficiens 
 suhlaxum (31). 
 
Bui. 622, U. S. Dept. of Agriculture. 
 
 Plate III. 
 
Bui. 622, U. S. Dept. of Agriculture. 
 
 Plate IV. 
 
THE TDENTTFTCATTON OF VARIETIES OF BARLEY. 25 
 
 seringev Koruicke (1882, p. 206. as var. ), a brown form of H. deficiens 
 
 stcudelii (26). 
 subatterbergii Kornicke (1908, p. 430, as var.), synonym for N. i. nudihaxfoni 
 
 nuditransicn^ (13). 
 subcompositum Kornicke (1908, p. 434, as var.), a compound form of H. 
 
 distichon nudum (21). 
 subhaxtoni Kornicke (1908, p. 429, as var.), an indefinite variation of H. i. 
 
 nudihaxtoni (13). 
 spurium, Atterberg (1899, p. 11), varieties witli ueitlier crease nor depression 
 
 at basfe of grain. 
 tetrastichum Kornicke (1822, p. 125), all lax vulgare. 
 
 tortile Seringe (1841, p. 349), a 6-rowed barley with malformed awns ap- 
 proaching hoods. 
 tortile Robert (1832, according to Seringe, 1841. p. 349), probably as above. 
 tortilis Heuze (1872, p. 457), probably as tortile Ser. 
 triangulare Kornicke (1908, p. 432, as var.), synonym for H. distichon angus- 
 
 tispicatum farcatozeocriton (19). 
 utriculatum K. H. in Beaven (1902, p. 579. as var.), synonym for H. distichon 
 
 laxuiii (23). 
 verum Atterberg (1899, p. 11), all varieties with transverse crease at base of 
 
 grain. 
 violascens, K. H. in Beaven (1902, p. 578, as var.), synonym for H. distichon 
 
 paluiella canescens (17). 
 walpersii Kornicke (1882, p. 182, as var.), synonym for H. v. coeleste (5). 
 
 LINES FOR FURTHER STUDY. 
 
 The various characters upon which varieties have been founded 
 have been discussed in connection with the keys and lists of varieties. 
 Between most of the characters retained in the keys, the distinctions 
 are quite sharp. There are a few, however, which are not exactly 
 clear and which offer attractive fields for study. 
 
 The question of color is not on an entirely satisfactory basis. 
 Colors are apparently the results of minor phases of metabolism, but 
 have been utilized in taxonomic work because of the fact that they 
 are conspicuous. Doubtless many more important features of metab- 
 olism are ignored in the grouping of varieties. Being a question 
 of metabolism, and usually one of the altered metabolism of ap- 
 proaching maturity, it is questioned whether environment may or 
 may not affect the production of pigment. This is particularly 
 worthy of stud}'^ in the blue and purple colors. 
 
 The variations of density are equally suggestive. There is no ap- 
 parent reason why a strain of any given density can not exist, and 
 in the grouping of varieties it would be worth while to know if there 
 is even a narrow gap between the dense and lax forms. Possibly 
 density, which has here been reduced to a subvarietal distinction, 
 may have to be eliminated altogether. The separation of deflciem 
 and distichon also presents possible difficulties. Hybrids of defiGiens 
 
26 BULLETIN 022, U. S. DEPARTMENT OP AGRICULTURE. 
 
 and distichon do not fall clearly into the two groups of their parents. 
 >■ How much the heterozygous character is responsible for the confusion 
 remains to be determined. How broad the interpretation of inter- 
 m.ediwm should be is also a matter of doubt. It may be that it should 
 include forms in which the lateral florets are sterile but pointed. 
 This would explain such forms as atterhergii Ivcke., which most prob- 
 ably are genetically nearer intetrniediuTn than distichon^ even though 
 "the pointing of the glume is a glume charactei' and not one of 
 fertility. 
 
 IDENTIFICATION OF THRASHED MATERIAL. 
 
 Of necessity the keys have been based on spike characters. Fre- 
 quently, however, it is necessary to identify a barley from thrashed 
 kernels alone. This is not always possible, but ordinarily the chance 
 of error is negligible, owing to the fact that only one of the series 
 of possibilities may with any likelihood occur under a given set of 
 conditions. The observations to be made are taken up in the order 
 in which they occur in the key. 
 
 By means of fertility only the first three species can be identified. 
 Dejiciens can not be separated from distichon w^ith certainty on the 
 basis of the grain alone. It may well be ignored, however, because 
 varieties of deficiens are rare. They occur naturally only in Abys- 
 sinia and Asia Minor. In the United States they are found on few 
 of our experimental stations and are almost unknown on farms. The 
 first determination is usually as to whether the sample is 2 rowed 
 or 6 rowed. This can be ascertained readily by the presence or 
 absence of the lateral kernels in the sample. If it is 2 rowed, of 
 course there will be no lateral kernels. As shown in Plate IV, figure 
 1, these lateral kernels can be identified by the twisted character. 
 On the spike their bases lie almost in the same plane as that of the 
 central kernel. Toward the tip, however, they gradually turn in- 
 ward until the planes of the furrows approach a right angle. When 
 the kernel is laid upon the dorsal side, this twist of the furrow ig 
 quite conspicuous. The species intermediwm usually can be dis- 
 regarded, because of the fact that it occurs very rarely. However, 
 it is separated easily from vulgare. The lateral kernels are not only 
 smaller than those of vulgare^ but the tips are either rounded or 
 (somewhat rarely) pointed, showing that neither awn nor hood had 
 been present in the spike. 
 
 The adherence of the flowering glume is, of course, more appar- 
 ent in the thrashed grain than in the spike itself, as the hulled and 
 naked barleys are most easily identified by thrashing. The determi- 
 nation can be made, however, without injury to herbarium material, 
 for the fine cross wrinkling never occurs on the lemmas of the naked 
 forms, and the freedom of the glumes is itself apparent at the junc- 
 ture of the lemma and palet. 
 
THE IDENTIFICATION OF VARIETIES OF BARLEY. 27 
 
 The color of the grain is also as apparent in thrashed material as 
 in the spike. The determination of the awned or hooded character 
 is next to impossible if the sample has been thrashed clean. Ordi- 
 narily enough kernels still bear fragments of awns or hoods, as the 
 case may be, to make this determination certain. If the barley has 
 been clipped, the determination may be impossible. Naked varie- 
 ties are more difficult to determine than hulled, and the identification 
 must depend upon the fragments of awns and hoods which are likely 
 to be present. Short, relatively thick kernels may be suspected of 
 being the Nepal, which is the hooded, white, 6-rowed naked barley, 
 but positive identification can not be made on this basis alone. 
 
 These characters carry the identification as far as the variety. If 
 it is desired to determine the subvariety, it is necessary to establish 
 the minor variations. This is not always possible, but fortunately 
 the most common variations are the easier to determine. The more 
 rare variations may be ignored with safety in 99 per cent of the 
 samples. The varieties with wide outer glumes can not be sepa- 
 rated from those with narrow glumes unless internodes from the 
 rachis are present with the outer glumes attached. This is usually 
 the case; but even if it were not, there is small chance of a wide- 
 glumed variety being present. 
 
 Any difficulty encountered in the determination of color is usually 
 confined to the separation of blue and white. As the blue color in 
 liulled barleys is located in the aleurone layer, it is best to strip the 
 lemmas from two or three grains, for weathering often so discolors 
 them that it is impossible to see the blue color beneath. Purple 
 color in these varieties is found in the glumes. In naked varieties 
 the color is more readily seen, but is difficult of determination in 
 immature specimens. Until well ripened, some white varieties have 
 a greenish cast which might easily be confused with the blue. The 
 blue and purple do not develop until near maturity. In blue barleys 
 especially the color may be very pale. In well-matured specimens, 
 however, there is little difficulty in making the determination. 
 
 The smoothness or roughness of the awns can be told if fragments 
 of awns persist on any of the kernels. If the lateral nerves of the 
 lemma are very scabrous, it may be taken for granted that the awns 
 were rough. Smooth-awned varieties are so rare, however, that this 
 may be disregarded. 
 
 Density usually can be determined from thrashed specimens, al- 
 though not with absolute certainty. In extreme cases the identifica- 
 tion is made easily. As shown in Plate IV, figure 2, there is a 
 transverse crease at the base of the lemma in the dense varieties. In 
 the lax ones there is a small horseshoe-shaped depression. The dense 
 varieties of 6-rowed barley usually have the base of the lemma elon- 
 gated, especially in the lateral florets. In most varieties of inter- 
 
28 BULLETIN 622, U. S. DEPARTMENT OF AGRTCULTTJRE. 
 
 'medium this extension is characteristic of tlie lateral florets of lax 
 varieties as well. In barleys with awnless lateral kernels the obser- 
 vation should be made upon the central kernel. In the naked varie- 
 ties density can not be determined with certainty from thrashed 
 specimens. 
 
 VARIETIES GROWN IN FIELD CULTURE IN THE UNITED STATES. 
 
 Students and experimenters usually are interested in the variation 
 that occurs in a crop as a whole, but there are also times when they 
 are concerned only with local forms. For this reason it has been 
 thought advisable to include a short list of the varieties and sub- 
 varieties which are grown in field culture in the United States. 
 Although a very small percentage of the total number of forms is to 
 be found, they are distributed through the groups in such a way as 
 to be quite representative. The only forms which are entirely lack- 
 ing are the deficient, wide-glumed, and smooth-awned varieties and 
 subvarieties. The wide-glumed forms are not found in pure culture 
 even at our experiment stations. Deficient barleys are grown at but 
 few stations, and smooth-awned varieties at even a less number. The 
 writer has a considerable number of smooth-awned selections in field 
 tests in cooperation with the Minnesota Agricultural Experiment 
 Station and elsewhere. Hordeum vulgare pallidum and H. distichon 
 palmellu include most of the agronomic varieties grown. The greater 
 proportion of varieties in each case is found in the lax subdivisions. 
 The following key includes a few well-known agronomic varieties 
 in each of the more common subvarieties. 
 
 KEY TO COMMERCIAL VARIETIES. 
 
 Spikelets all fertile (6-rowed barleys). 
 
 Lateral florets awned or hooded (sp. vulgare). 
 Kernels hulled. 
 
 Lemmas awned. 
 
 Kernels white, blue, or purple (var. pallidum). 
 Kernels white. 
 
 Spilie -narrow, lax, nodding subvar. typica. 
 
 Represented by the agricultural varieties Man- 
 churia, Oderbrucker, Tennessee AVinter, and 
 white strains of Coast (Bay Brewing), etc. 
 Spike wide, very dense, pyramidal, awns widely 
 
 spreading subvar. pyramidatum. 
 
 Representetl by the agricultural varieties Win- 
 ter Club (White Winter or Utah Winter), 
 Tapps Winter, and Mariout. 
 
 Kernels blue subvar. coerulescens. 
 
 Represented by blue-gray strains of Coast and 
 several pedigreed selections of Manchuria. 
 
 Kernels black var. nigrum,. 
 
 Represented by the agricultural variety Gatami. 
 
THE JDENTIFICATION OF VARIETIES C)E BAKLEY. 29 
 
 Spikelets all fertile (6-rowed barleys) — Continued. 
 
 Lateral florets awned or hooded (sp. vulyarc) — Continued. 
 Kernels hulled — Continued. 
 
 Lemmas hooded var. hor.sfordianuni. 
 
 Represented by the agricultural variety Hors- 
 ford Beardless (Success Beardless). 
 Kernels naked. 
 
 Lemmas awned. 
 
 Kernels white, blue, or purple (var. coelcstc). 
 
 Kernels white subvar. typica. 
 
 Represented by .Jeriisalem barley and other 
 naked varieties, usually not named. 
 
 Kernels blue subvar. Jiiinolayense. 
 
 Represented by the agricultural variety Hima- 
 laya Hull-le.ss (Guy Mayle). 
 
 Kernels purple.: subvar. violaceum. 
 
 Represented by the agricultural variety Black 
 Hull-less. 
 
 Lemmas hooded "-var. trijurcatum. 
 
 Represented by the agricultural variety Nepal 
 (White Hull-less). 
 Lateral florets rounded or pointed, neither auned noi- liooded (si), inlcr- 
 meclinm). 
 
 Kernels hulled. 
 
 Lemma of central floret awned or awnless (var. hnrtoni). 
 
 Lemma of central floret awnless subvar. ionsitiii. 
 
 Represented by the agricultural varieties Ar- 
 lington Awnless, Famesh, and in the dense 
 form by Nakano Wase. 
 Central spikelets only fertile, lateral sterile or wanting (2-rowed barley). 
 Lateral florets present (sp. distielion). 
 Kernels hulled. 
 
 Lemmas awned. 
 
 Kernels white, blue, or purple (var. pnlmcUa). 
 Kernels white. 
 
 Spike nan-ow. lax. nodding subvar. nuiarni. 
 
 Represented by the agricultural varieties 
 Hanna, Hannchen, Moravian, I'rincess. Chev- 
 alier, etc. 
 
 Spike wide, dense, erect subvar. erectum. 
 
 Represented by the agricultural varieties Svan- 
 hals. Primus. Goldthorpe, etc. 
 
 Kernels black var. niiiriconx. 
 
 Represented by the aeiMcultural varieties Black 
 Smyrna and Black Arabian. 
 Kernels naked. 
 
 Lemmas awned. 
 
 Kernels white : var. nudum. 
 
 Represented by the agricultural variety Mc- 
 Ewans, etc. 
 
 No attempt has been made in the above key to distinguish between 
 the agronomic varieties within a subvariety. It is hoped to make 
 
30 BULLETTlSr 622, U. S. DEPARTMENT OP AGRICULTURE. 
 
 these separations in a later publication. In the varieties at present 
 groAvn in America, separations are most difficult in the lax forms 
 of the common 6-rowed barleys. In general, there are two groups, 
 the Manchuria- Oderbrucker and the Coast. These groups are sepa- 
 rated by the longer, heavier grain and the more tenacious awn of the 
 latter. Within a group such as the Manchuria, identifications must 
 be based on combinations of minor characters, such as the density 
 of the spike, the nature of the hairs on the rachilla, the length of 
 grain, and, if necessary, distinctive culm characters and the length 
 of the growing season. 
 
 SUMMARY. 
 
 The variations that occur in barley are of importance to the 
 student, agronomist, plant breeder, and pathologist. They offer a 
 Avide opportunity for selection, breeding, and studies of disease 
 resistance. In barley the forms are unusually numerous and clearly 
 defined. The number and character of the types existing are more 
 concisely indicated by a classification of variations than in any 
 other way. 
 
 The groups of barley have been arranged upon the basis of species, 
 varieties, and subvarieties. Only major characters have been used in 
 describing species and varieties ; less important characters have been 
 utilized in describing subvarieties. Under each subvariety there may 
 be an unlimited number of agronomic varieties. Four species and 
 32 varieties are recognized. 
 
 All groups have been made to conform with previous usage as far 
 as possible. One of the principal aims of the writer of this bulletin 
 has been to state clearly the form or group intended to be described 
 by each published name. Except for their historical significance, 
 the subvarieties would not have been continued, and no forms have, 
 been added to them. 
 
 Four varieties have been added. 
 
 Lists of rejected terms and varieties are included. 
 
 The keys can be adapted to the identification of thrashed grain 
 by a number of characters. In the common agronomic varieties the 
 chance of error in the identification of thrashed grain is slight. 
 
LITERATURE CITED. 
 
 Alefeld. F. G. C. -~- 
 
 1866. Landwirthschaftliche Flora ... 363 p. Berlin. 
 Atterbeeg, Albert. 
 
 1889. Die Erlveunuug der Haupt-Varietiiten der Gerste in den nordeuro- 
 paischen Saat- und Malzgersten. In Landw. Vers. Stat., Bd. 36, 
 p. 23-27. 
 1891. Die Klassifikation der Saatgersten t^^ord-Europas. In LandW. Vers. 
 
 Stat., Bd. 39. p. 77-80. 
 1S99. Die Varietiiten und Fornien der (ierste. In .Jour. T.audw.. Bd. 47, 
 Heft 1, p. 1-44. 
 Beaven, E. S. 
 
 1902. Varieties of barley. In .Tour. Fed. Inst. Brewina:. v. 8, no. a, p. ,142- 
 593, 12 fig. Discussion, p. 594-600. 
 Carleton, M. a. 
 
 1916. The Small Grains. 699p., illus. New York. Bibliography, p. 639-<585. 
 Dalechamps, .Jacques. 
 
 1615. De I'Histoire Generale des Plantes . . . faite fraugoise par lean des 
 Moulins. 2 v., illus. Lyon. 
 Doll, J. C. 
 
 1857. Flora des Grossherzogthunis Baden. Bd. 1. Garlsruhe. 
 Eriksson, Jakob. 
 
 1889. Collectio Cerealis. ^'arietates Crealiuin in Suecia Maturescentes 
 continens. Fasc. 1, 10 p., 2 fig. Stockholm. 
 Haller, Alberti de. , 
 
 1776. Genera, species et varietates cerealium. Senno II. Hordeum, secale. 
 avena. In Novi Comm. Soc. Reg. Sci. Gott., t. 6, p. 1-22, pi. 2-4 
 (fold). 
 Harlan, H. V. 
 
 1914. Some distinctions in our cultivated barleys with reference to their 
 use in plant breeding. U. S. Dept. Agr. Bui. 137, 38 p., 16 fig. 
 Literature cited, p. 37-38. 
 Heuze, Gustave. 
 
 [1872.] I^es Plantes Alimentaires. 2 v., illus. Paris. 
 1896-97. Les Plantes Oereales. ed. 2. 2 v., illus. Paris. 
 Hochstetter, C. F. 
 
 1848. Nachtraglicher Commentar zu meiner Abliandlung: "Aufbau der 
 Graspflanze, etc." . . . In Flora, Jahrg. 31 (n. R., Jahrg. 6), No. 7, 
 p. 105-118 ; No. 8, p. 121-135 ; No. 9. p. 140-1-32 ; No. 10. p. 1.54-167 ; 
 No. 11, p. 171-188. 
 Hoffmann, H. 
 
 1877. Culturversuche. In Bot. Ztg., Jahrg. 35, No. 17, p. 265-279 ; No. 18, 
 p. 281-295 ; No. 19, p. 297-305. pi. 3. 
 .Jessen, C. 
 
 1855. Samenkatalog des Eldenaer Botauischen Garten. (Not seen.) 
 
 KORNICKE, F. A. 
 
 1873. Systematische Uebersicht der Cerealien und IMonocarpischen Legu- 
 
 minosen ... 55 p., 1 tab. Bonn. 
 1882. Die saatgerste. Hordeum vulgare L. sensu latiore. In Ztschr. 
 Gesamm. Brauw., v. 5, p. 113-128, 161-172. 177-186, 193-203, 205- 
 208, 304-311, 329-336. 393-413, pi. 5-14. 
 1895. Die hauptsjichlichsten Fornien der Saatgerste ... 15 p. Bonn. 
 1908. Die Entstehung und das Verhalten neuer Getreidevarietaten. Hrsg. 
 von M. Kornicke. In Arch. Biontologie, Bd. 2, Heft 2, p. 389-437. 
 
 and Werner, Hugo. 
 
 1885. Handbuch des Getreidebaues. 2 Bd. Berlin. 
 Lamarck. J. B. P. A. de M. de, and Candolle, A. P. de. 
 
 1815. Flore Frangaise . . . ed. 3, t, 3. Paris. 
 Langsdorff. 
 
 1860. Landwirtschaftliche-Botanische Gartens der Gartenbauschule in 
 Karlsruhe Kulturpflanzen. {Not seen.) 
 
 31 
 
32 BULLETIN (522, U. S. DEPARTMENT OF AGRICULTURE. 
 
 Linn:e (Linmieus), Carl von. 
 
 1748. Hortus Upsalieu,si.s . . . t. 1, 306 p., 3 fold. pi. Stockholmiae. 
 1753. Species Plantarum . . . t. 1. Holmise. 
 Regel, Robeet. 
 
 1906. Les Orges Cultivees de FEmpire Russe. 39 p. Milan. 
 1908. lachmeni s glatskinii ostiami. (Glattgrannige Gei'sten.) hi Bill. 
 Bur. Angew. Bot., .Tahrg. 1, No. 1/2, p. 5-64, 84-85. (German trans- 
 lation, p. 64-85.) 
 
 Flaksbeeger, Constantin, and Malzew, a. I. 
 
 1910. Bazhnieishiia forniy pshenits lachnienei i sornykh rastenii Rossi'i. 
 (The most important forms of wheat, barley, and weed plants of 
 Russia.) In Bui. Bur. Angew. Bot., Jahrg. 3, No. 6, p. 209-282, 
 illus. Also reprinted. 
 RoEMER, J. J., and Schultes. J. A. 
 
 1824. Mantissa . . . Sytematis Vegetabilium ... v. 2. Stuttgardtiae. 
 
 ROYLE, J. F. 
 
 1839. Illustrations of the Botany and other Branches of the Natural His- 
 tory of the Himalayan INIountains, and of the Flora of Cashmere. 
 472 p. (and atlas of 100 col. pi.). London. 
 
 SCHLECHTENDAHL, D. F. L. VON. 
 
 1837. Hordeum coeleste trifurcatum H. Monsp. In Linnea, Bd. 11, Heft 4, 
 
 p. 543-544. 
 
 ^ptrij A T)irR "FT A 
 
 1838. Gramineae. In Linnea, Bd. 12, Heft 4, p. 423-476. 
 
 SCHUEBLEB, GUSTAV. 
 
 1818. Dissertatio Inaugui'alis Botanica sistens C'haracteristicen et Descrip- 
 
 tiones Cerealium in Horto Academico Tubingensi et in Wiirtem- 
 bergia ... 47 p., pi. Tubingse. Inaugural dissertation. 
 Sebinge, N. C. 
 
 1819. Monographie des Cereales de la Suisse . . . In his Melanges Botan- 
 
 iques, no. 2, p. 65-244, pi. Berne. 
 1841-42. Descriptions et figures des cereales Europeennes. In Ann. Soc. 
 
 Roy. Agr. Lyon, t. 4, p. 321-384, pi. 1-9, 1841; t. 5, p. 103-196, 
 
 pi. 2-10, 1842. 
 Serees, Olivier de. 
 
 1615. Le Theatre d' Agriculture et Mesnage des Champs. 907 p., illus., 
 
 fold. pi. Paris. 
 
 Steudel, E. G. 
 
 1855 [1854]. Synopsis Plantarum Glumacearum. Pars. 1. Gramineae. 
 474 p. Stuttgartiae. 
 
 Voss, A. 
 
 1885. Versuch einer neuen Svstematik der Saatgerste. In Jour. Landw., 
 Jahrg. 33, Heft 3, p. 271-282. 
 
 Willdenow, K. L. 
 
 1809. Enumeratio Plantarum Hortii Regii Botanici Berolinensis . . . 1099 
 p., and sup. 70 p. (in 2 v.). Berolini. 
 
 WiTTMACK, L. 
 
 1884. Ueber eine neue Gersten varietal. (Abstract.) In Ber. Deut. Bot. 
 
 Gesell., Bd. 2, p. Ixi. 
 
 1885. [Ueber eine Jistige Gersten-Aehre. 1 (Abstract.) In Sitzber. Gesell. 
 
 Naturf. Freunde Berlin, 1885, p. 1-3. 
 
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