658 



FAMILIES OF ANGIOSPERMS. 



stem is cylindrical, and marked by distinct nodes, as in the corn 

 plant. The leaves possess a sheath and blade. The flowers 

 form a loose head of a type known as a panicle. Each little 

 cluster as shown in fig. 541 is a spikelet, and consists usually 

 here of one or two fertile flowers below and one or two unde- 

 veloped flowers above. We see that there are several series 

 of overlapping scales. The two lower ones are "glumes," 

 and because they bear no flower in their axils are empty glumes. 

 Within these empty glumes and a little higher on the axis of the 

 spike is seen a boat-shaped body, formed of a scale, the margins 

 of which are folded around the flowers within,, and the edges 

 inrolled in a peculiar manner when mature. From the back of 

 this glume is usually borne an awn. If we carefully remove 

 this scale, the "flower glume," we find that there is another 

 scale on the opposite (inner) side, and much smaller. This is 

 the"palet." 



1149. Next above this we have the flower, and the most prom- 

 inent part of the flower, as we see, is the short pistil with the two 

 plume-like styles, and the three stamens at fig. 543. But if we 



are careful in the dissection 

 of the parts we shall see, on 

 looking close below the pis- 

 til on the side of the flower- 

 ing glume, that there are 

 two minute scales (fig. 545). 

 These are what are termed 

 the lodicules, considered by 

 some to be merely bracts, 

 by others to represent a pe- 

 rianth, that is two of the 

 sepals, the third sepal hav- 

 ing entirely aborted. Ru- 

 diments of this third sepal 

 GI, glumes; B, are present in some of the 

 gramineae. 



1150. To the gramineae belong also the wheat, barley, corn 



Fig. 546. 



Diagram o f oat spikelet. 

 palets; A, abortive flower. 



