220 CLAS.SIFI(;ATION OK HICK 



Leaf. — ^The first diagnostic character noticeable in the young 

 rice plant is the colour of the fii'st leaf sheath. This can be observed 

 five days after sowing. The nornuil colour is yellowish green, or a 

 green usually distinctly lighter than the colour of the leaf. In 

 certain classes, however, the coloui' is a shade of red or purple, in 

 the latter case sometimes almost bordering on black. The colour 

 may extend throughout the length of the leaf sheath, or may be 

 confined to the lower portion, just above the ground level. The 

 coloui' may fmther be either temporary or permanent, (lenerally 

 speaking, the deeper shades are lasting, while the lighter shades may 

 or may not disappeai' latei'. One ititerestiiig correlation has been 

 observed in connection with the coloured leaf sheath. All rices 

 which have a coloured leaf sheath have a dark coloured apiculus to 

 the glume and palea. The converse is possibly also true, but there 

 are still a few exceptions which are probably due to a very fleeting 

 colour in the leaf sheath. 



Coloured Rice. — In one variety of lice the ])lant is a bronze 

 purple red and a field planted with this variety foiins a striking 

 contrast to its verdant neighbours. This is due to a coloured 

 sap in the cells of the epidermis. In the young leaves the colour 

 is developed mainly in the epidermal cells lying in the furrows be- 

 tween the sclerenchyma ridges. As was pointed out by Mooker- 

 jee(ll) this variety would be a convenient one to select for intro- 

 duction on account of the ease with which a field could be rogued. 

 I agi'ee with Kikkawa(12) in his decision that from an agricultui-al 

 point of view the difference in colour should not be made a main 

 point in a scheme of classification. From a systematic stand-point 

 the colour of rice might well be described as a variety. 



Liqule.—Vw the developed leaf another diagnostic character is 

 found. The ligule which in the rice is continued round the sheath of 

 the leaf as two ears or " sickles "(13) is either a light yellow colour 

 or may be black with red. In the latter case the stem appears to 

 have coloured bands or garters round it. These coloured sickles 

 are commonly associated with a coloured leaf sheath, but the 

 association is bv no n\eans invariable, as more than one rice with a 



