﻿SOME NEW VAJUKTIKS OF HICK. 



DESCRIPTION OF THE RICE PLANT. 



Most of the varieties of rice cultivated in this country belong to 

 the species Oryza sativa L. They are annual grasses with fibrous 

 roots extending outward and downward in all directions from the 

 crown, which is located about \\ inches above the lower end of the 

 culm. The distribution of the roots usually is 

 outward and very near the surface of the soil. 

 Under normal conditions most of the roots do not 

 extend to a greater depth than 3 to 5 inches. 

 When grown without irrigation and before the 

 irrigation water is applied when irrigated, the 

 roots penetrate the soil more deeply than when 

 the soil is submerged. Adventitious roots (Fig. 

 1, B) arise from the first, second, and third nodes. 

 They are more conspicuous in some varieties than 

 in others and often are produced under irrigation 

 when the water level is suddenly lowered or raised. 



The culms of the rice plant are erect, cylindrical, 

 and hollow, with solid nodes. They vary in length 

 from approximately 2 to 6 feet, depending largely 

 upon the variety, but to a certain extent upon the 

 soil and probably other factors. The number of 

 culms to a plant varies greatly, usually ranging 

 from 3 to 12. The wall of the culm in the lower 

 internodes is thick. That of the peduncle, below 

 the panicle, is much thinner but still strong. In 

 color the internodes are light green to yellowish 

 green. They are sometimes streaked with brown 

 or purple. The nodes usually are darker green or 

 brown. 



The leaves vary in number from five to eight. 

 As a rule, there are six, including two basal leaves, 

 one of w T hich may wither and become detached 

 before the plant matures. The sheath nodes, or 

 swollen bases of the leaf sheaths (Fig. 1, A), are 

 conspicuous and usually a light green. The 

 sheaths (Fig. 1, C), which are open in part, are 

 much shorter than the blades. They are green 

 and occasionally marked with purple on their 

 inner surface near the base. The auricles are 

 hairy and prominent (Fig. 2, Z?), and may be 

 light yellow or green, cartilaginous or membra- 

 nous. The ligules (Fig. 2, A) are prominent, 

 light yellow or sometimes light green, acute or 

 obtuse, and often split for their entire length. 

 The blades (Fig. 2, D) vary in width from a little 

 less than half an inch to 1 inch and in length from 16 to 20 inches. 

 They are erect or ascending, visually the latter, and prominently 

 veined. Their surfaces are glabrous or puberulent. though some- 

 times rough, particularly toward the apex. The apex is acute or 

 acuminate. Narrow blades are characteristic of the short-grain 

 varieties of rice. 



Fig. 1. — A part of 

 the two lower in- 

 ternodes of a en 1 m 

 of rice, showing 

 sheath node (A), 

 adventitious roots 

 (B), and loaf 

 sheath (C). The 

 leaf sheath has 

 been removed to ex- 

 pose the adventi- 

 tious roots. (Nat- 

 ural size.) 



