14 



Botanical Section 



[PT I 



the lodicules 1 , and are considered to represent bracteoles (i.e. 

 secondary bracts) subtending the flower. The ovary and stamens 

 —the essential parts of the flower — are enclosed between two 

 boat-shaped scales called the palece. These palese are also 

 considered to be of the nature of bracts or bracteoles, i.e. enveloping 

 protective organs. The inner or upper palea is usually thin and 

 sometimes membranous ; the outer or lower palea is larger, stouter, 

 and more or less overlaps the inner one, and frequently bears a 

 bristle-like appendage or awn. Morphologically the awn bears 

 the same relationship to the outer palea as the leaf-blade bears to 



Fig. 17. Floral diagram of a typical grass. The outer palea (o.p.), and the 

 inner palea (i.p.) enclose two bracteoles (the lodicules) (I.), three stamens (£.), 

 and the ovary (ov.). st. the stigmatic plumes, a. axis=rachilla. 



the leaf-sheath. Very useful distinctive characters are afforded 

 by the nature of the awn and its position on the palea. 



The SpiJcelet. Each spikelet or partial inflorescence consists 

 of a little spike of flowers with their palea? arranged as shown 

 diagrammatically in Fig. 18, the whole being enclosed by one 2 

 or more (usually two) bracts called the empty glumes— or briefly 

 the glumes. The flower and spikelets of the Oat are large and 

 afford good material for examination. 



Forms of Inflorescence. The form of inflorescence is determined 



1 In a few genera the lodicules are absent, e.g. Alop°curus, Anthoxanthum, etc. 



2 Except in Nardui, where the glume is obsolete. 



