. A classification of the cultivated varieties of barley ... Barley. A Classification of the Cultivated Varieties of Barley 393 each internode just as the main axis of the spike does. These likewise arise near the base of the spike. Occasionally such deviations as are mentioned above are more or less con- stant, but more often they are found to be variable, due to environmental conditions. In either case they have no economic importance and very little taxonomic value. Consequently they are not used in the present classifi- cation as characters of importance in separating groups or even variet
. A classification of the cultivated varieties of barley ... Barley. A Classification of the Cultivated Varieties of Barley 393 each internode just as the main axis of the spike does. These likewise arise near the base of the spike. Occasionally such deviations as are mentioned above are more or less con- stant, but more often they are found to be variable, due to environmental conditions. In either case they have no economic importance and very little taxonomic value. Consequently they are not used in the present classifi- cation as characters of importance in separating groups or even varieties. Density The density of the spike in barley, by which is meant the number of florets to the unit length of rhachis, has been employed by all taxonomists in the classification of barleys, in one form or another. In the greater number of cases it has been given equal weight with fertility in the formation of either species or subspecies. In fact, density has been considered by many authors as a result of varying degrees of fer- tility. This, however, can easily be disproved by making comparative weights of the kernels of the lateral and central spikelets of either com- mon or erect six-rowed varieties. There is .just as much difference between these two groups of spikelets in the erect varieties as in the common. The groups according to density have gen- erally been divided into dense and lax forms. For the sake of varietal descrip- tion, Kornicke (1885) even mentioned a division of the dense forms into dense and very Fig. 54. two-bowed barley A, Spike of branch-headed two-rowed barley; B, one internode of the rhachis with its abnormalities. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wiggans, Roy Glen, 1891- [from old catalog]. [Ithaca
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbarley, bookyear1921
