534 POACE^ 



culms flattish, sheaths usually mu(;]i shorter than the internodes; 

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

 scabrous or smootli, 10-13 cm. long, 1.5-2 mm. Avide, very gradu- 

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

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

 long, rays capillary, flcxuose. mostly in pairs oi' threes, the longest 

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

 Spikck'ts jiale green, rarely tinged with purple, open, oval, ;]-6- 

 flowered, 4-T mm. long, joint of racliilla 0.8 -O.H mm. long; lirst 

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

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

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

 pubescent on the marginal nerves ami lower half of the keel, oval, 

 obtuse or enuirgimite, 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, Srrihncr 3489 from "Wheeler; District of Columbia, 

 T7?se//G4l; Tennessee, Curtiss 3849 from Gattinger; Mississii)pi, 

 Tracy. 



Dry or wet woods or swamps, Pennsylvania, ^lichigan to Texas. 



Var. robusta Vasey, Contrib. U. S. Nat. Herb. 1:271 (1803). 



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

 ligule 2-4 mm., long; blades 4-G mm wide; panicle 17-25 cm. 

 long. It difl'ers from the species in having webby hairs at the 

 base of the florets aiul in the erect panicle. 



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



Xot seen by me. 



S. P. brevifolia Muhl. Gram. 138 (1817). P. pungnis Xutt. 

 Gen. 1 :66 (1818). P. cuspidafa Ts'utt. Barton, Comp. Fl. Phila. 

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



Culms smooth flattish, 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; ligule obtuse, 1 mm. long; blades 1-5 

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

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



