112 CLASSIFICATION ACCORDING TO [CH. 
Some forms of F. ovina are viviparous (see p. 134), and several 
varieties have to be distinguished. 
©© Awns hair-like and dorsal on the palee. Flowers 
two in each spikelet. Annual, six inches or less 
in height. 
Aira precoa, L. 
The rare A. canescens, L. also comes here: its awn is jointed and 
with a minute tuft of hairs about the middle. 
(11) Panicle lax and open, the fine hair-like branches 
spreading widely during florescence, or even 
pendent or drooping. 
* Spikelets awnless. 
+ <A small aquatic grass with prostrate habit and 
two-flowered spikelets with broad truncate 
glumes and pale. 
Catabrosa aquatica, Beauv. (Fig. 4). 
The two-flowered spikelets distinguish it at once from Glyceria 
aquatica, to say nothing of its softer and smoother texture and 
small stature. Poa trivialis may have two flowers, but it is an 
erect meadow-grass, with keeled and pointed glumes and palez. 
Aira and Agrostis are awned, or differ entirely in habit. 
tt Spikelets with at least three or four, but usually 
more flowers. 
© A perennial field-grass with few large, 
compressed, bluntly triangular or ovate 
spikelets, dangling at the end of capil- 
lary branchlets; with membranous, 
loosely wmbricated, concave and in- 
flated palee and glumes, and 6—8 
flowers. 
Briza media, L. 
The much rarer B. minor, L. is an annual and smaller. 
