POACEAE 



139 



65. Briza L. 

 I. B. minor L. In ballast and waste places: N. J. to Va. Na- 

 tive of Europe. 

 Rare as a weed. 

 1 B. media L. has been reported from Conn, as a waif. It is a native of Eutope. 



66. Dactylis L. 

 1. D. glomerata L. In fields and waste places: N. B. to Br. Col., 

 south to Fla. and Cal. 

 Common everywhere. 



67. Cynosurus L. 

 1. C. cristatus L. In fields and waste places: Newf. to Ont., 

 southern N. Y. and N. J. Native of Europe. 

 Rare as a weed. 



68. Poa L. 



Annual. 

 Perennials. 



Culms tufted, usually densely so. 



Flowering scales not webby at base. 

 Flowering scales webby at base. 



Flowering scales glabrous; culms obviously com- 

 pressed. 

 Flowering scales somewhat pubescent; culms usually 

 cylindric. 

 Lateral nerves of the flowering scales glabrous. 

 Plant yellowish green; flowering scale 2.5 



mm. long. 

 Plant green; flowering scale 3.5 mm. long. 

 Lateral nerves of the flowering scales pubescent. 

 Spikelets 4 mm. long or less; panicle- 

 branches dividing and spikelet- 

 bearing at or below the middle. 

 Intermediate nerves of the flowering 



scale obscure. 

 Intermediate nerves prominent. 



Midnerve of flowering scale pu- 

 bescent only below; spikelets 

 crowded on the branches. 

 Midnerve pubescent its whole 

 length; spikelets scattered on 

 the spreading branches. 

 Spikelets 5 mm. long or more; panicle 

 branches usually dividing and spikelet- 

 bearing only at the end. 

 Culms not tufted; rootstocks long, creeping. 



1. P. annua. 



2. P. autumnalis. 



3. P. debilis. 



4. P. trivialis. 



5. P. alsodes. 



6. P. triflora. 



7. P. pratensis. 



8. P. sylvestris. 



9. P. brachyphylla. 

 10. P. compressa. 



