MONO CO T YLEDONS : LI LI A CEjE. 



657 



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 (gramineas) one may take the 



Fig. 541. 

 Spikelet of 

 oat showing 

 two glumes. 



Fig. 542- Fig- 543- 



One glume re- Flower opened 



moved showing showing two palets, 



fertile flower. three stam< 



, 

 nd 



Fig. 544- 

 Section show- 

 ng ground plan 



laree biitmciis, iinu 

 two lodiculesat base 

 of pistil. 



545- 



Flower of 

 pat, show- 

 ing the upper 

 palet behind, 

 and the two 

 lodicules in 



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 



