I7 6 FIELD OATS. 



Cut a transverse section of the blade, and note 



6. The variable thickness of the leaf. 



7. The sections of the fibre-vascular bundles. 



8. On the upper edge, large cells between the ridges, the 

 hygroscopic cells, which cause the leaf to roll when dry. 



E. THE FLOWERS. 



i. The arrangement of the flowers, anthotaxy. Note 



a. The central stem of the flower cluster, the main 

 axis of inflorescence. 



b. Its lateral branches, secondary axes. Notice their 

 relative lengths. 



c. That some of the secondary axes are branched, 

 others not, thus constituting a panicle. 



d. Make a diagram of the mode of branching. 



e. That each ultimate branch bears not a single 

 flower, but a cluster of three (sometimes two) 

 flowers, a spikelet, at the thickened extiemity. 

 The entire inflorescence is thus compound, a 

 panicle of spikelets. 



Detach a spikelet, and note 



/. Two bracts at the base of the spikelet, completely 

 inclosing the flowers, the empty glumes. Notice the 

 position of these glumes with respect to each 

 other and their points of attachment. Detach 

 them, and note 

 i. Their shape. 



ii. The parallel veins, nerves ; the number in 

 each glume, the termination above, the deli- 

 cate cross (anastomosing) veinlets. 

 iii. Draw. 



