GENERAL MORPHOLOGY. 15 



The Leaves. — A leaf arises from each node of the stem and consists 

 of the sheath, the ligule, and the blade. 



The sheath clasps the stem closely and its edges overlap, completely 

 covering 1 the stem from the node from which it starts almost to the 

 node above. The midrib is prominent in the sheath, as is shown in 

 the sectional view in Plate II, tig. 1. The edges of the sheath are often 

 streaked with purple, which color may also extend into the ligule or 

 even into the blade of the leaf, being usually more pronounced near 

 the margins of the part in which it occurs. 



The lisrule of the leaf is the thin, membranaceous extension of the 

 sheath at the base of the blade, which clasps the stem above the sheath. 

 (PI. II, tig. 1.) 



The blade of the leaf is peculiar chiefly in that its midrib is not in 

 the center, being a little nearer one margin than the other. Those 

 leaves which arise from the basal node or from the first node above 

 the base are the ones which appear upon the surface of the water 

 before the stem is developed. After the stem appears these floating 

 leaves cease to function and wither away. The upper leaves, wdiich 

 are supported by the stem, do all the elaborating work after the stem 

 appears and remain green and vigorous until after the seeds of the" 

 plant are mature. 



The Panicle. — The panicle may be considered as having two areas — 

 the staminate, which occurs below, and the pistillate, which occurs 

 above. The staminate portion of the panicle consists of whorls of 

 spreading branches arising from the joints of the axis. These pri- 

 mary branches bear numerous secondary branches, which in turn bear 

 the flowers or spikelets. 



The staminate spikelet consists of two unequal, soft, purple or pale 

 green glumes inclosing six bright yellow stamens. The larger glume 

 has five nerves and the other three. The larger glume bears a short, 

 soft beak, and its edges overlap those of the smaller glume in the 

 unopened spikelet. The stamens, after the spreading of the glumes, 

 break open along their entire length and shed their bright yellow 

 pollen out into the air. when it is carried by the wind to the stigmas 

 of adjacent plants. 



Cross fertilization of wild rice is insured because the pistillate por- 

 tion of the panicle appears first from the leaf sheath and the stigmas 

 have appeared and been pollinated by other plants before the staminate 

 spikelets of the same plant have been released and opened. 



The pistillate portion of the panicle is in the method of branching 

 similar to the staminate portion, except that the branches are usually 

 borne nearly or quite erect, in some cases being closely appressed to 

 the main axis. The amount of spreading of the branches of the pistil- 

 late portion of the panicle is one of the important distinguishing 

 marks between the varieties of wild rice. The spreading is due to the 



