CHAPTER XX 
Tripe VIII. AGROSTIDEA 
A LARGE tribe of about 50 genera inhabiting more 
especially the temperate and cooler regions of the world. 
Spikelets 1-flowered (the rachilla prolonged as a stipe 
behind the palea in a few genera) usually perfect, arranged 
in open, contracted or spike-like panicles, but not in 1-sided 
spikes or racemes. The spikelets are jointed with the 
pedicel in a few genera, and fall off entire (Alopecurus, 
Cinna, Polypogon, Lycurus, Limnodea). The palea is 
usually 2-nerved but in Cinna it appears to be 1-nerved, 
the 2 nerves lying close together. In some species of 
Agrostis the palea is a small nerveless scale or is wanting. 
In some genera the floret is raised slightly from the glumes 
on a hard stipe, the short internode of the rachilla.” This 
remains attached to the floret at maturity as a hard point 
and is called the callus.. This callus is pronounced in 
Stipa and Aristida and less so in Oryzopsis, Muhlen- 
bergia and a few other genera. In some species of Calama- 
grostis the short callus bears numerous silky hairs as long 
as the floret. 
KeryY TO THE GENERA OF AGROSTIDEZ 
a. Lemma indurated at maturity, firmer than 
the glumes, closely enveloping the caryopsis 
and usually the palea, awned (except in 
Milium) from the tip, or mucronate (some 
speeies of Muhlenbergia). 
sp. Awn trifid (the lateral awns sometimes 
short, rarely wanting)..................-ARISTIDA 
Be. Awn simple. (Par. 229). 
(196) 
