GRASS FAMILY. 



15* 



Panicle open, the branches more or less spreading, at least at maturity 



Pedicels equalling or shorter than the spiki-U ts : fi r >t M-al<- al>..tit iialf an lone m the itcond 

 Branches of the panicle verticillate. 



Spikelets K'Mong green. s argtlhtt 



Spikelets i % -i l /z long, purple. , , 



Branches of the panicle alternate or sometimes sub verticillate. 



Spikelets about i" long; first scale lanceolate. . 



Sheaths naked or sparingly ciliate at the throat; panicle usualh 



Sheaths densely pilose at the throat; base of the panicle generally included. 



Spikelets 2"-2&" long; first scale subulate. 



Pedicels at least twice the length of the spiki-K-N; first scale about equalling t! 

 Culms erect, simple; leaves elongated. 



Culms slender, from an annual root; outer sc-ali-s alxmt half the Irngth of the uptkrlrt. 



Culms stout, from a horizontal rootstock: outer scales slightly shorter than thr .j 



1 6 

 Culms decumbent and branched below; leaves short. 17 .V <ji/ 



i. Sporobolus asper (Michx.) Kunth. Rough Rush-grass. (Fig. 34 



Agroslis aspera Michx. PI. Bor. Am. I: 57. 

 Sporobolus asper Kunth, Knum i: 210. 1833. 



Sporobolus asf>er var. Di am ///,.;/,/// Vasey, Conlr. 

 f. S. Nat. Herb. 3: 6a 1892. 



Culms 2-5 tall, erect, simple, smooth and 

 glabrous. Sheaths shorter than the interned**; 

 ligule a mere ring, less than )t " long, naked; 

 leaves 3'-i5' long, \"-i" wide at the batt, 

 attenuate into a long slender involute tip, 

 smooth and glabrous beneath, scabrous above. 

 or somewhat hairy at the base; panich- 2 

 length, linear, strict, its branches i'-a' long, ap- 

 pressed; spikelets $"-4" long, thr outi-r scales 

 unequal, acute; third scale pubescent at the base, 

 much longer than the second and greatly ex- 

 ceeded by the long-acuminate almost awned 

 palet. 



In dry soil, Delaware to Illinois, south to Florida 

 and Texas. Aug -Sept. 



2. Sporobolus longifolius (Torr. ) Wood. 



(Fig. 342.) 



Agroslis longifolia Torr. Fl. U. S. i: 90. 1824. 

 Sporobolus asper Vasey, Contr. U. S. Nat. Herb. 3: 



59. 1892. Not Kunth, 1833. 

 Sporobolus longifolius Wood, Class-book, 775. 



1861. 



Culms i l / 2 -Z l A tall, erect, simple or occa- 

 sionally branched, smooth and glabrous. 

 Sheaths shorter than the internodes; ligule very 

 short, minutely ciliate; leaves 4 / -i8 / long, i"- 

 2" wide at the base, attenuate into a long slen- 

 der involute tip, smooth and glabrous beneath, 

 scabrous and hairy at the base above ; panicle 

 more or less included in the upper sheath, 3'- 

 10' in length, linear, strict, the branches i r -2 

 long, erect; spikelets 2 // -2 / ^ // long; outer scales 

 unequal, acutish, glabrous, the lower shorter; 

 third scale glabrous, acutish or obtuse, exceed- 

 ing the second and equalling or a little shorter 

 than the obtuse palet. 



In dry soil, Maine to Pennsylvania, Missouri and 

 Kansas, south to Florida and Texas. Aug -Sept. 



Long-leavc'l Rush-grass. 



