STRUCTURE. 13 



in Milium effusum ; crowded when the branches are so 

 short that the florets are close together, as in Panicum 

 verticillatum ; and nodding when the branches droop, as 

 in Aira ccespitosa. It is digitate when the spikes are 

 collected in a cluster like the fingers of a hand, as in 

 Panicum sanguinale. 



A spikelet is composed of three or more scales or bracts, 

 called glumes, the two outer of which are nearly always 

 empty. This, however, cannot be considered as by any 

 means a rule, for it is a characteristic of some genera to 

 have only one empty glume, or the second one so rudi- 

 mentary as to be scarcely visible. Sometimes, on the 

 other hand, there are more than two empty glumes ; but 

 these may be considered as exceptions, and two empty 

 glumes to a spikelet as the rule. These glumes occupy 

 the position of the calyx of other flowers. The third 

 glume, when only three are present, is characterized as 

 the flowering -glume. Opposite to this, or between it 

 and the axis, is generally placed a smaller and thinner 

 scale, more or less distinctly ribbed, and called a palea ; 

 the flowering-glume and palea represent the corolla of 

 other blossoms. 



The glumes are awned or awnless, ribbed, fringed, bifid, 

 pointed, or blunt. The palese are subject to similar va- 

 rieties of form. 



Each floret, if perfect, contains its flowering-glume and 

 palea, its ovary, style, and stigma, its three stamens, and 

 often one or two scales attached to the base of the ovary. 



The stamens vary in number from two to six, but with 



the exception of Anthoxanthum odoratum,, all our British 



, genera have three. The anthers are of cellular structure, 



linear form, notched at both ends, and coloured with 



white, yellow, saffron, or purple. The scales at the base 



