534 POACEiB, 



ciilms flattisli, sheaths usually much shorter than the internodesj 

 ligule obtuse, lacerate, 0.7 mm. long; leaves of sterile shoots flat^ 

 scabrous or smootli, 10-12 cm. long, 1.5-2 mm. wide, very gradu- 

 ally taper- pointed, those of the culm 3-4 in number, 4-7 cm. long, 

 flat or conduplicate. Panicle very diffuse, pyramidal, 7-10 cm. 

 long, rays capillary, flexuose, mostly in pairs or threes, the longest 

 5-6 cm. long, bearing 2-4 pedicelled spikelets near the apex. 

 Spikelets pale green, rarely tinged with purple, open, oval, 3-6- 

 flowered, 4-7 mm. long, joint of racliilla 0.8-0.9 mm. long; first 

 empty glume lanceolate, 1-nerved, 1.7-2.3 mm. long, second linear- 

 lanceolate, scabrid on the keel, 3-nerved; 2.5-3.5 mm. long, floral 

 glume 2.7-3.2 mm. long, thin, a few webby hairs at the base, 

 pubescent on the marginal nerves and lower half of the keel, oval^ 

 obtuse or emarginate, the lateral nerves within O.G mm. of the 

 conspicuously scarious apex ; palea 2-3 mm. long, linear, 2-toothed, 

 scabrid on the keels. 



Michigan, Scribnei- 3489 from Wheeler; District of Columbia, 

 Vase?/ Ml; Tennessee, Curtiss 3849 from Gattinger; Mississippi, 

 Tracu. 



Dry or wet woods or swamps, Pennsylvania, Michigan to Texas. 



Var. robusta Vasey, Contrib. U. S. Nat. Herb. 1:271 (1893). 



Culms 75-90 cm. high, sheaths shorter than the internodes; 

 ligule 2-4 mm. long; blades 4-6 mm wide; panicle 17-25 cm» 

 long. It differs from the species in having webby hairs at the 

 base of the florets and in the erect panicle. 



Colorado, Vasey 367, alt. 8000-9000 feet, Jones. 



Xot seen by me. 



S. P. brevifolia Muhl. Gram. 138 (1817). P. pimgcns Nutt. 

 Gl'Ii. 1:66 (1818). P. cuspidata Nutt. Barton, Comp. Fl. Phila. 

 1: 61 (1818). P. brachyphylla Schult. Mant. 2: 304 (1824). 



Culms smooth flatfish, 20-50 cm. high, from creeping root- 

 stocks. Leaves of sterile shoots rather numerous, the blades mostly 

 flat, 20-30 cm. long, 2-3 mm. wide, apex acute, leaves of the culm 3 

 in number, sheaths scabrous; ligvile obtuse, 1 mm. long; blades 1-5 

 cm. long. Panicle open, thin, oval or pyramidal, 6-10 cm. loug, 

 rays in twos, threes, or fours, slender, spreading, the lower often 



