66 



FIRST BOOK OF GRASSES 



FIG. 57. Spike- 

 let of rice 

 (Oryza saliva) . 



FIG. 58. Spike- 

 let of Homa- 

 locenchrus ory- 

 zoides. 



In Lesson IV, Figs. 23 (page 32) and 

 24 (page 32), we had unisexual spike- 

 lets, the staminate and pistillate on 

 distinct plants. Wild rice, Zizania 

 palustris (Fig. 59, A and B), is monoe- 

 cious, staminate and pistillate spikelets 

 borne in the same panicle, the awn- 

 less staminate ones pendulous on the 

 spreading lower branches, the awned 

 pistillate ones erect on the ascending 

 upper branches. In the pistillate spike- 

 let the suppressed glumes are repre- 

 sented by a very shallow ridge around 

 the base of the spikelet. The staminate 

 flower consists of six stamens instead 

 of three, as in the grasses studied here- 

 tofore. The palea of this spikelet is 



FIG. 59. A, pistillate spikelet, and B, staminate spike- 

 let, of Zizania palustris. 



