POACEAE I I 7 



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

 northward. 117-220 days. Sea level-4,050 ft. 



62. P. Boscii Poir. (P. Porterianum Nash. P. pubifolium Nash). 



In woods: Mass. to Mo., Okl., Fla. and Tex. 



Throughout the range except the pine-barrens and the region 

 east of them. 



63. P. clandestinum L. (P. decohratum Nash). In thickets and 



moist places: Me. to Kan., south to Fla. and Tex. 



Throughout the range, except the pine-barrens. 



P. barbipulvinatum Nash has recently been reported from Rockaway Peninsula and 

 Long Beach, L. I. by E. P. Bicknell. Rhodora 16: 82. May 1914. 



15. Sacciolepis Nash. 



1. S. striata (L.) Nash. In swamps: N. J. to Okl., south to 

 Fla. and Tex. Also in the W. I. 

 Known only from Cape May Point, N. J., in our area. 



16. Amphicarpon Raf. 



1. A. Amphicarpon (Pursh) Nash. In moist pine-barrens; N. J. 



N. J. Common in the pine-barrens, decreasing southward to Cape 



May. 



Tertiary, common on Beacon Hill, rare elsewhere*: Cretaceous, 

 o: Older Formations, o. 159-220 days. About sea level. 



17. Chaetochloa Scribn. [Setaria Beauv.] 



Bristles downwardly barbed. I. C. verticillata. 



Bristles upwardly barbed. 



Inflorescence racemose; second scale shorter than the spikelet; 

 bristles 5-16, involutrate. 

 Annual; spikelets exceeding 3 mm. long; bristles yellowish 



brown. 2. C. glauca. 



Perennial; spikelets 3 mm. long or less; bristles green, 

 yellowish, or purple. 3. C. imberbis. 



Inflorescence paniculate; second scale as long as the spikelet; 

 bristles 1-3, not involucrate. 

 Fruiting scales dull, faintly rugose, obtuse, rather thin. 

 Inflorescence 2.5-7 cm - l° n g> l - 2 s cm - thick or less; 



spikelets about 2 mm. long; bristles green. 4. C. viridis. 



Inflorescence 10-20 cm. long, 1.25-5 cm - thick; spike- 

 lets about 3 mm. long; bristles usually purple. 5. C. italica. 

 Fruiting scales shining, perfectly smooth, very acute, hard. 6. C. magna. 



* See Introduction paragraph 29. 



