LIFE HISTOKY AND DESCRIPTION. 13 



LIFE HISTORY AND NATURAL PROPAGATION. 



The wild-rice plant is an annual. It bears abundant crops of seeds 

 which fall directly into the water as soon as ripe and lie buried in the 

 mud below until the following spring - when, if conditions are favor- 

 able, they germinate and produce new plants. In the northern lakes 

 the long ribbon-like leaves appear floating upon the surface of the 

 water late in May. By the latter part of June the stems have grown 

 sufficiently to raise the leaves above the water. In the South the 

 growth starts much earlier. On the mud flats of the lower Potomac 

 the plants may be 6 inches high by the 1st of Ma} T . Strange as it may 

 seem, the period of flowering and ripening of wild rice is almost the 

 same in northern Minnesota and along the Potomac River near Wash- 

 ington, though on account of the earlier start in the southern region 

 the period of growth is much longer. 



The panicles appear during the latter part of July, and the flowers 

 open immediately. The glumes of the pistillate flowers separate at 

 the base to allow the stigmas to protrude and be pollinated and clos- 

 ing again soon after fertilization is accomplished leave the withered 

 stigmas outside. Immediately after fertilization the young seed 

 begins to elongate, and gradually fills the space within the floral 

 envelope. This development requires about two or three weeks, and 

 as soon as it is completed the connection with the stem is weakened 

 and the seed falls off. The time of maturing of the different seeds in 

 a single panicle extends over several days, the seeds on the tips of the 

 branches ripening first. 



The seeds on falling usually strike the water with the point of 

 attachment below and sink immediately to the bottom. If by accident 

 the distal end strikes first, enough small particles of air are caught by 

 the barbs borne there to keep the seed on the surface of the water for 

 a time, but as these air bubbles escape the seed sinks. 



BOTANICAL DESCRIPTION. 



Zizania aquatica L. is an aquatic, annual, monoecious grass. The 

 stems are tall, erect, and hollow. The leaves are long and flat, with a 

 heavy midrib, usually slightly nearer one margin of the blade than the 

 other. 



The flower cluster is a large panicle, bearing the staminate flowers 

 on spreading branches below and the pistillate flowers on erect and 

 more or less closely appressed branches above. The floral bracts are 

 two in number, the outer five and the inner three nerved. The stami- 

 nate flowers have six stamens. The pistillate flowers are borne with 

 the larger glume toward the axis of the plant. The styles are nearly 

 separate and stand at right angles to the floral axis, protruding on 

 either side of the outer glume during and after fertilization. 



