570 POACE^. 



mm. long, 7-nerved, apex subacute to truncate, entire, slightly- 

 denticulate or obscurely lobed; palea narrow, 2-toothed, about 3.5 

 mm. long. 



Vermont, Pringle; Massachusetts, Beal 119; Pennsylvania, 

 Scribner for U. S. Dept. Agricul. 685 ; Michigan, Dr. Clark 207, 

 Cooleij, Beal 116, 117, Wheeler, Farwell; Illinois, Bealll^-, Min- 

 nesota, Arthur X 5, B 30; Oregon, HotveU. 



Found in shallow water in temperate regions of North America, 

 Europe, northern Africa, western Siberia, Himalaya, and Australia. 

 The Australian plant has narrow blades; so have plants (No. 45) of 

 Nat. Hist. Surv. of Minn. In the latter they are often condupli- 

 cate. The floral glume of a plant from Berlin, Germany, is 5.5 

 mm. long, while one from Minnesota is 3.5 mm. long. The blades 

 of the plants from Niles, Michigan, and one from Oregon are 

 scabrid. 



10. P. acutiflora (Torr.) Kuntze, Rev. Gen. PL 782 (1891). 

 Ghjceria acutiflora Torr. Fl. U. S. 1 : 104 (1824). 



Perennial, with creeping rootstocks; culms 60-120 cm. high. 

 Sheaths smooth, compressed; ligule about 6 mm. long; blades of 

 the culm about 4 in number, erect, nearly smooth, flat, 10-12 cm. 

 long, 3-4 mm. wide. Panicle included at the base, simple, slender, 

 loose, 20-30 cm. long, lowest rays in pairs, one very short, the other 

 2 cm. long, beside the single spikelet. Spikelets erect, pale, terete, 

 2-3 cm. long, 7-13-flowered, joint of rachilla 3 mm. long; empty 

 glumes linear-lanceolate, 1-nerved, first 4 mm. long, second 6 mm. 

 long; floral glume scabrid, oblong-lanceolate, usually acute, 7-8 

 mm. long, 7-nerved; palea lanceolate, 8-9 mm. long, 2-toothed, 

 scabrous on the keels. 



Massachusetts, Dr. Sturfevafit; Pennsylvania, Scribner 248, 

 Martindale. 



Wet places, Maine to Tennessee; rather rare. 



132. (259 a). Atropis Rupr. Fl. Samoj. [Beitr. Fl. Russ. 

 Reich. 2:] 64 (1845). IhjdrocMoa Ilartm. Gram. Skaud. 8 (1819), 

 not Beauv. PuccinelUa Pari. Fl. Ital. 1:366 (1848). 



Spikelets 2-9-flowered in a panicle usually contracted after 

 flowering, rachilla articulate between the flowers. Empty glumes 



