w 4. Poa L. Bluegrass. 
Annuals or perennials with narrow, flat or folded blades with boats =| 
shaped tips. spikelets 2 to severel flowered, disarticulating above the 
glumes and between the florets; glumes keeled, the first usually 1, the 
second d-nerved; lemmas more or less keeled, 5-nerved, avmless, glabrous, 
pubescent, or with a cobweb at the base, the tip often scarious and shining. 
O Plants annual le Pe annua 
O Plants perennial 
2 Rhizomes present 
4 Culms much compressed; panicles dense, she short 
@ branches appressed or stiffly spreading ce P. compressa j 
4 Culms not compressed, or only slightly so; panicles 
3g open, the branches flexuous, naked below : 
6 Lemmas glabrous or sparsely pubescent on the back 
{0 below; cobweb wanting oe Pe nervosa 
a 
(, Lemmas densely pubescent on the keel and marginal F 
JQ nerves; cobweb present 4. P. pratensis 
Ww \ ce 2, Rhizomes wanting, Palns tufted 
ee : 
4 Cobweb present, sometimes scant ; 
6 Culms loose and decumbent at the base, the lower 
/o sheaths compressed, keeled Oo. P. palustris 
Soe ET eed 
(, Culms densely tufted, erect, the lower sheaths 
jgrounded on the back 6. P. interior 
ac nendliydt ceil late 
4 Cobweb wanting¢) 
G Lemmas densely pilose on the keel and marginal nerves 
7. P. alpina 
a me bees | 
(, Lemmas glabrous, scabrous or crispepubescent 
/p00n the back below, the nerves not densely pilose 
i A rai ite el se 
G Culms buloous at the bases spikelets proliferous 14. P. bulbosa 
-  Culins not bulbous; spikelets normal 
J/g vemaas crisp-pubescent on the back below 
te Culms decumbent at the base, loosely tufted; 
Ww ‘{/(, panicle branches sproading 8. P. gracillima 
(2 Culms erect, densely tufted; panicles 
/{, narrow, the branches appressed 
ee ae i ee ee 
ee tl el Be ae 
