POACEAE 141 



Tertiary, o: Cretaceous, only adventive: Older Formations in- 

 creasing northward. 1 17-189 days. Sea level-3,365 ft. 



7. P. pratensis L. In woods, thickets, fields and waste places: 



nearly throughout N. Am. Also in Eu. and Asia. 

 Common throughout the range. 



8. P. sylvestris A. Gray. In thickets and meadows: N. Y. to 



Wise, Neb., south to Fla. and Tex. 



Rare and local as an apparent adventive, with us. 



9. P. brachyphylla Schult. (P. brevifolia Muhl.). In rocky 



woods: southern N. Y. to 111., Ga. and Tenn. 



N. J. Rare in Warren and Hunterdon counties, near the Delaware; 



also in Burlington and Cape May counties (according to Stone). 

 Pa. Northampton, Bucks, Philadelphia, Delaware and Chester 



counties. 



Tertiary, o: Cretaceous, rare: Older Formations, rare and 

 scattered. 148-207 days. Sea level-680 ft. 



10. P. compressa L. Waste places and cultivated grounds: 

 nearly throughout N. Am. Native of Europe. 

 Locally abundant as a weed, often in woods and thickets. 

 Poa crocata Michx. and P. nemoralis L. have both been recorded as waifs in our area. 



69. Panicularia Fabr. 



Spikelets ovate or oblong, 8 mm. long or less. 



Flowering scales very broad, obscurely or at least not 

 sharply nerved. 

 Panicle open, the branches ascending or spreading, 

 often drooping. 

 Spikelets 3-5 flowered ; lowest flowering scale about 



2 mm. long. I. P. laxa. 



Spikelets 5-12 flowered; lowest flowering scale 



about 3 mm. long. 2. P. canadensis. 



Panicle contracted, the branches erect. 3. P. obtusa. 



Flowering scales narrow, sharply and distinctly 7-nerved. 



Panicle elongated, its branches erect or appressed. 4. P. Torreyana. 



Panicle not elongated, open, its branches spreading 

 or drooping, rarely erect. 

 Scales about 2 mm. long, obtuse or rounded at 

 the apex. 

 Spikelets 3 mm. long or less; panicle branches 



often drooping. 5. P. nervata. 



