28 BULLETIX 622, U. S. DEPARTMEXT OF AGEICULTURE. 
'medium this extension is characteristic of the 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 Avith the Minnesota Agricultural Experiment 
Station and elsewhere. Hordeum culgare paUidum and H. distichon 
palmelJa include most of the agronomic varieties groAvn. 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-rowecl barleys). 
Lateral florets awned or hooded (sp. viilgare). 
Kernels hulled. 
Lemmas awned. 
Kernels ^Yhite. blue, or purple (var. pnUidiim). 
Kernels white. 
Spike narrow, lax. nodding subvar. fypiea. 
Represented by the agrictiltural varieties Man- 
churia, Oderbrucker, Tennessee Winter, and 
white strains of Coast (Bay Brewing), etc. 
Spike wide, very dense, pyramidal, awns widely 
spreading subvar. pyramid at urn. 
Represented by the agricultural varieties Win- 
ter Club (White Winter or Utah Winter), 
Tapps Winter, and Mariout. 
Kernels blue subvar. coemlescens. 
Represented by blue-gray strains of Coast and 
several pedigreed selections of Manchuria. 
Kernels black var. nigrum. 
Represented by the agricultural variety Gatami. 
