10 THE TRUE GRASSES. 



Inflorescence. — Distinction must be made between the 

 special inflorescence, the spikelets — which will be re- 

 ferred to farther on — and the entire inflorescence. The 

 latter arises by monopodial division of the upper portion 

 of the culm, and the branching may be in different 

 degrees : when the primary branches form single spike- 

 lets and the lowest glumes of these are apparently 

 sessile upon the main axis, the inflorescence is a spike 

 (which is really compound) ; if the bases of these pri- 

 mary branches are naked, forming a pedicel, it is a raceme; 

 and if the spikelets are only upon secondary or farther 

 divided branches, a panicle. The inflorescence is yet 

 more complicated in many Andropogonea 3 , Panicece, and in 

 Maize, where the branches of the panicle bear racemes, 

 whose spikelets, however, are borne partly on primary 

 and partly on secondary branchlets of these racemes. 

 The primary branches of the whole inflorescence are 

 most frequently alternately two-ranked, and more rarely 

 (as in many Andropogonem, Panicece, Sporobolus, Eragros- 

 tis, etc.) spirally arranged ; in the latter case they are 

 often in whorls of from 2 to 4 members. The two-ranked 

 arrangement is often altered by the more rapid growth 

 of one side of the main axis (the side which is turned 

 more away from the earth in the bud) ; the spikelets ac- 

 cordingly move toward one side and the inflorescence 

 becomes one-sided, as is especially noticeable Avith the 

 panicles of Dactylis and Cynosurus, and the spikes of the 

 CMoridece. 



This appearance is intensified by the relations of the 

 secondary branches. According to the laws of anti- 

 dromy (see page 6), the first secondary branches all 

 fall upon the same side of the culm ; since these mostly 

 arise near the base and are again branched, this side of 

 the main axis appears to be much richer in spikelets. 

 Where the secondary branches also arise near the base 

 and are as strongly developed as the primary ones, the 

 inflorescence regains a symmetrical appearance (Poa 

 pratewis, P. trivicdis). If the branches are short and lie 

 close to the main axis and all the internodes of the 

 branches remain short, the result is a cylindrical, false 



