568 



POACE^. 



mm. long; floral glume broadly oval when spread, 2-2.3 mm. long, 

 7-nerved; palea nearly as long as its glume, incurved. Spikelets 

 smaller, less turgid and greener than those of P. Canadensis. 

 Maine (:\rt. Desert, Seal Harbor), J. H. Redfield in 1894. 

 7. P. Americana (Torr.) MacMillan, Metasp. Minn. 1:81 

 (1892). Poa aqnatica var. Americana Torr. Fl. U. S. 1:108 

 (1824). G. aquatica J. E. Smith, Engl. Fl. 116 (1824), not 

 AYahl. G. graudis S. AVats. A. Gray, Man. Ed. 6, 6G7 (1890). 

 Panicularia aquatica (L.) Kuntze, Rev. Gen. PL 782 (1891). 



A robust perennial, with creeping rootstocks; culms 90-150 cm. 



high. Sheatlis mostly shorter than 

 the internodes ; ligule 2-3 mm. long ; 

 blades 4-5 in number, flat, smooth 

 or scabrid, 30-60 cm. long, 8-15 

 mm. wide. Panicle oblong or oval, 

 20-40 cm. long, rays numerous, 

 ascending, nodding, bearing many 

 spikelets. Spikelets oblong or 

 linear-oblong, usually purplish, 5- 

 9-flowered, 4-6 mm. long, joint of 

 racbilla 0.7 mm. long; empty 

 glumes oblong or oval, acute or ob- 



FiG. 114. — Panicularia Americana. 

 Spikelet. (Ricliardson). 



tuse, 1-nervcd, first 1.5-2 



long, second 2.5-3 mm. long; floral 

 glume oval, 2.5 mm. long, 7-nerved, apex truncate, obtuse, often 

 denticulate under a lens; palea elliptical, 2-toothed, nearly 2.5 mm. 

 long. 



Massachusetts, Beal 115; Michigan, Coolen, Clarh 2055; Min- 

 nesota, Arthur B 97, B 263; Montana, Anderson 70; Colorado, 

 Cassidy; Dakota, Duffey; Wyoming, Buffum C 52. 



Wet grounds, Canada to Montana, New Mexico, Northern States 

 to Tennessee. 



8. P. pauciflora (Prcsl) Kuntze, Rev. Gen. PI. 783 (1891). 

 Glyceria jjauci/lora Presl, Rel. Ilrenk. 1:257 (1830). 



A robust perennial, 30-120 cm. high, from creeping rootstocks. 

 Sheaths shorter than the internodes, or longer, in small plants; lig- 



