FESTUCE^. 533 



5. P. subaristata Scribn. Macouu Cat. Cau. PI. 4:227 (1888). 

 No description. 



A slender densely tufted perennial, 20-40 cm. high. Blades 

 of sterile shoots conduplicate, scabrid, 5-10 cm. long. 0.5-1 mm. 

 diam., sheaths of culm 2, smooth, the upper extending to near the 

 middle of the whole height; ligule 1 mm. long; upper blade pun- 

 gent, 0.5-2 cm. long. Panicle linear to oval, dense, somewhat 

 interrupted, 3-6 cm. long, more or less tinged with purple. 

 Spikelets linear-lanceolate, 4-7-flowered, 6-9 mm. long; emjity 

 glumes subequal, liuear-lanceolate, 5 mm. long, one-nerved; floral 

 glume 6 mm. long, scabrid on the nerves, not webbed, liuear- 

 lanceolate; palea narrowly linear before sj^reading, 5 mm. long, 

 ciliolate on the keels. 



Yellowstone Park, F. Tweedy 633. 



6. P. Cusickii Yasey, Contrib. U. S. Nat. Herb. 1:271 (1893). 

 A glabrous tufted perennial, 30-40 cm. high. Sterile slioots 



numerous, blades conduplicate or involute-filiform, 10-15 cm. long, 

 0.3 mm. diam. ; leaves of the culm 2, the lower sheaths longer than 

 their interuodes; ligule decurrent, 2-3 mm. long, blades flat or 

 involute, acute, 3.5-5 cm. long, 1.5 mm. wide. Panicle more or 

 less exserted, narrow, 6-10 cm. long, rays mostly in twos, the 

 longest 3-4.5 cm. long, bearing 4-8 spikelets on tlie outer half. 

 Spikelets narrowly to broadly oval, 6.7 mm. long, 2-3-flowered, 

 rachilla hispidulous, empty glumes with broad chartaceo-liyaline 

 margins, first ovate-lanceolate when spread, 3.5 mm. long, 1-nerved, 

 rarely 3-nerved; second oval, erosely acute, 4-4.5 mm. long, 

 3-nerved; floral glume keeled, 4.2-5 mm. long, scabrous, oval 

 wlien spread, subacute; palea 4.4 mm. long, 2-toothed, ciliate on 

 the keels. 



Oregon, Cusick for U. S. Dept. Agricul. 1219. 



7. P. autumnalis Muhl. ; Ell. Bot. S. C. & Ga. 1:159 (1817). 

 P. flexuosa Muhl. Gram. 148 (1817), not J. E. Smith. P. 

 j)nngens Torr. Fl. U. S. 1:109(1824), not Xutt. (1818). P. 



r'ampyle Schult. Mant. 2: 304 (1824). P. EUiottii Spreng. Syst. 

 1 : 338 (1824). 



A soft slender smootli tufted perennial, 30-SO cm. liigli; 



