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To distinguish A. falua from the remaining species. 
c. The distinct articulation between the grains and their axes. 
To distinguish A. brevis and A. slrigosa from A. sativa and A. sativa orientalis. 
d. The awn points or teeth of the lemma. 
To distinguish A. sativa orientalis from A. sativa. 
e. The unilateral panicle. 
To classify varieties of all groups. 
f. 1. Habit of early growth. 
2. Color of grains. 
3. Liguie and auricle — present or absent. 
4. Awns — present or absent, and their character if present. 
5. Hairs of callus (basal hairs) — present or absent, and their character if present. 
6. Hairs of lemma — present or absent. 
7. Hairs of rhachilla — present or absent, and their character if present. 
8. Rhachis — form and nodes. 
9. Cilia of leaves — present or absent. 
10. Nerves of lemma — number and character. 
11. Color of immature plant. 
12. Spikelets — attitude and number of grains. 
13. Form and length of grains. 
14. Panicles — form. 
15. Culms — relative size. 
Hi. Double-grains. 
17. Relative maturing period. 
In addition to the above characters, the following may be employed 
in general description: 
1. Dimensions of panicles. 
2. Dimensions of leaves. 
3. Quality of culms. 
4. Height of plants. 
5. Relative length of sheath. 
Physical properties of the grains, such as weight and proportion of 
kernel to hull, are too easily influenced by environment to be reliable in 
classification. 
The characters employed for the complete differentiation of each of 
the main specific groups — A. sterilis, A. sativa, and A. sativa orientalis — 
are not used in regular order, but according to expediency in classification. 
Thus the color of grains may be the chief distinction of subgroups, or it 
may be merely a supplementary character in the identity of small sections 
or single varieties; and. other characters are often transposed in a similar 
manner. Such irregularity in the use of characters seems justified, how- 
ever, in a classification which, like the present one, is artificial within 
the specific groups. A classification of the cultivated varieties of any 
crop could proceed but little beyond the arrangement of a few main 
groups if it were limited to a strictly logical and systematic use of charac- 
