570 POAf'E.E. 



mm. long, 7-nerved, apex subacute to truncate, entire, slij^htly 

 denticulate or obscurely lobcd; palca narrow, ".'-tootlied, about :),'> 

 mm. lon<,'. 



Vermont, Prinyh'; .Massachusetts, Ucal lli>: Pennsylvania, 

 Scribner for U. S. Dcpt. Agricul. G.S.j: Miobi^'an, hr. Clark '201, 

 Cooh'ii, 1ie((l 110, lir. Wheehi; Favm-U; Illinois, Beal US; Min- 

 nesota, Arthur X 't. li riO; (^)regon, JIoiccll. 



Found in shallow water in temperate regions of Xorth America, 

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

 The Australian i)lant has narrow blades; so have j)lants (No. 45) of 

 Xat. Hist. Surv. of Minn. In the latter they are often eondupli- 

 eate. The floral glume of a plant from Berlin. CJernnmy, is .").'» 

 mm. long, while one from Minnesota is 'AJ> mm. long. The blades 

 of the plants from Xiles, ^lichigan, and one from Oreg'> i aa; 

 scabrid. 



10. P. acutiflora (Ton.) Kuntze, l{ev. (Jen. PI. T83 (ISIM). 

 Ghjceria arn/ijlora Torr. Fl. V. S. 1 : 104 (1S24). 



Perennial, with creeping rootstocks; culms r)0-l:20 cm. high. 

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

 the culm about 4 in number, erect, nearly smooth. Hat, 10-1'J cm. 

 long, ,^-4 mm. wide. Panicle included at the base, simple, sleiuler, 

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

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

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

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

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

 mm. long, T-nerved; i)alea lanceolate, 8-9 mm. long, 3-toothed, 

 scabrous on the keels. 



Massachusetts, Dr. Sturfevanf; Pennsylvania, Scribner 348, 

 Martindale. 



AVet places, Maine to Tennessee; rather rare. 



133. (350 a). Atbopis Rupr. Fl. Samoj. [Beitr. Fl. Russ. 

 Reich. 3:] 04 (1845). Hydrochloa Ilartm. Oram. Skand. 8 (1819), 

 not IJeauv. PucctneUia Pari. Fl. Itid. 1:300 (1848). 



Spikelets 3-9-flowcred in a panicle usually contracted after 

 flowering, rachilla articulate between the flowers. Emjity glumes 



