6 BULLETIN- 622^ U. S. DEPARTMEI^T OF AGEICULTUEE. 
division of the appendages to the lemma and one of the outer glumes 
have been again separated into two subdivisions. The resulting 
number of possible varieties is in consequence ver}^ 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 normal 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 bear bristlelike projections. In most varieties 
of this group only part of the lateral florets are 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 jD'alet. Rudimentary ovaries and stamens are never found. 
Barlej^s 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 kernel 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 onl}?" the two 
