MONO CO T YLEDONS : LILIA CE&. 



6 57 



its parts are all formed. Sometimes in places well exposed to 

 the sun the pollen is already developed in the autumn, while in 

 other cases it is formed during warm days in the winter or in 

 early spring, always before the flower opens above ground. In 

 connection with these studies one should consult Parts III and 

 IV. Relation of Plants to Environment, Ecology. 



Topic II: Monocotyledons with a glume subtending 

 the flower (Glumiflorae). 



ORDER GRAMINALES. 



1148. Lesson II. Grass family (Gramineae). Oat. As a 



representative of the grass family (graminese) one may take the 



Fig. 541. Fig. 542. Fig. 543. Fig. 54 4. 



Spikelet of One glume re- Flower opened Section show- ing the upper 

 oat showing moved showing showing two palets, ing ground plan palet behind, 



two glumes. fertile flower. 



three stamens, and of flower. , 

 two lodicules;.t base 

 of pistil. 



xis. and the two 

 lodicules in 

 front. 



oat plant, which is widely cultivated, and also can be grown 

 readily in gardens, or perhaps in small quantities in greenhouses 

 in order to have material in a fresh condition for study. Or we 

 may have recourse to material preserved in alcohol for the dis- 

 section of the flower. The plants grow usually in stools; the 



