51 



Series B .— P0A0E2E. 



Spikelets 1- to roany -flowered, the imperfect or rudi- 

 mentary flower, if any, usually uppermost; rachilla 

 usually articulated above the empty glumes, so that 

 these remain after the fall of the fruiting glumes. 1 In 

 spikelets with two or more flowers these are separated 

 by a manifest internode of the rachilla, and in such 

 cases the rachilla is usually articulated below each 

 flowering glume. 



In this second grand division of the Gramineae the 

 pedicels are not (or very rarely) articulated below the 

 outer glumes but the axis of the spikelet is articu- 

 lated above these glumes, so that they usually remain 

 attached to the pedicel after the falling off of the mature 

 florets. The spikelets are one- to many-flowered, and 

 have as many flowering glumes as there are flowers; 

 the imperfect flowers, when present, are the upper- 



| most; the terminal floret may be staminate or rudi- 



| mentaiy. 



KEY TO THE TRIBES IN SERIES B. — POACEJE. 



1. Spikelets 1-flowered, with or without a simple continuation of 

 the rachilla behind the palea 2 



1. Spikelets two- to many-flowered 5 



2. Spikelets crowded in two (rarely one) rows along one side of a 



continuous rachis forming unilateral spikes, these scattered 

 along a common axis or digitate at the apex of the 

 stem Tribe X. Chlorides. (See page 97) 



2. Spikelets not disposed in unilateral spikes 3 



3. Inflorescence spicate, the spikelets sessile on alternate teeth or 



notches of the rachis. . . Tribe XII. Horded. (See page 157) 



3. Inflorescence racemose (not unilateral) or paniculate, occasion- 



ally contracted and spike-like, or condensed and apparently 

 capitate; spikelets always distinctly pedicellate 4 



4. Glumes five, the first four empty or (in Savastana) the third 



and sometimes the fourth, which are usually very unlike the 

 first and second, with staminate flowers; the fifth glume with 

 a hermaphrodite flower, and falling with the third and fourth; 

 palea 1-nerved Tribe VII. Phalaride^e. (See page 53) 



!In Alopecurus, China, Polypogon, Spartina, Beckmannia, Limnodea, and Holms 

 the rachilla is articulated below the empty or outer glumes, and the spikelets 

 fall off entire. 



