DIVERSELY SPECIALIZED SPIKELETS 



65 



from the normal type (such as a 1-awned palea would 

 be), it is advisable to reexamine and to reconsider. 

 A close examination of this fertile floret will reveal 

 the thin edges of the lemma infolding the palea. 

 A grain may always be recognized by the embryo 

 at the base on the back. (See Fig. 5, A). 



In Torresia (called holy-grass, vanilla-grass, or 

 Seneca-grass) the sterile florets are awnless and con- 

 tain paleas and stamens. Like Anthoxanthum, the 

 whole plant is fragrant. These are 

 the grasses of which sweet-grass bas- 

 kets are made. 



In Phalaris the glumes are enlarged 

 and strongly keeled or, as in canary- 

 grass, P. canariensis (Fig. 56), wing- 

 keeled, and the sterile florets are re- 

 duced to small empty lemmas. In 

 one species, P. minor, the first sterile 

 floret is reduced to a minute rudi- 

 ment, and in the common reed 

 canary-grass, P. arundinacea, both 

 sterile lemmas are narrow and hairy. 



In Lesson VII, Fig. 42 (page 50), we 

 had an example of greatly reduced 

 glumes. In rice, Oryza sativa (Fig. 

 57), the glumes are minute, and the 

 lemma and palea are indurate (hardened) and com- 

 pressed laterally. Some varieties of rice have an 

 awned lemma. In an allied genus, Homalocenchrus 

 (Fig. 58), the glumes are wholly suppressed. 



Fig. 56. A, spikelet 

 of Phalaris cana- 

 riensis; B, fertile 

 floret with pair of 

 small sterile florets 

 attached at base. 



