152 



GRAMINEAE. 

 Sporobolus pilosus Vasey. Hairy Rush-grass. (Fig. 343.) 



Sporobolus pilosus Vasey. Coult. Bot. Gaz. 16: 26. 1891. 



Culms i-ij tall, erect, rigid, stout, smooth and 

 glabrous. Sheaths shorter than the internodes, 

 crowded and overlapping at the base of the culm ; 

 ligule very short, minutely ciliate ; leaves 3 / -6 / long, 

 J//-2" wide at base, erect, rigid, attenuate into a slen- 

 der involute tip, the lower papillose-hirsute on both 

 sides, the upper usually glabrous beneath, scabrous 

 above and somewhat hairy near the base ; panicle 

 2'-$' in length, included at the base, erect, strict, 

 its branches %'-\ f long, erect; spikelets 2%" long, 

 the outer scales unequal, glabrous, obtuse, the lower 

 shorter ; third scale obtuse, glabrous, somewhat ex- 

 ceeding the second and equalling or a little longer 

 than the obtuse palet. 



In dry soil, Kansas and Missouri. Aug.-Sept. 



4. Sporobolus vaginaeflorus (Torr. ) Wood. 



(Fig. 344.) 



Vilfa z-aginaeflora Torr. ; A. Gray, Gram, and Cyp. No. 3. 



1834- 



Sporobolus vaginaeflorus Wood, Classbook, 775. 1861. 

 Sporobolus minor Vasey; A. Gray, Man. Ed. 6, 646. 1890. 



Culms S'-i8' tall, erect, slender, smooth or scabrous. 

 Sheaths usually inflated, about half as long as the 

 internodes; ligule very short; leaves i" wide or less, 

 smooth and glabrous beneath, scabrous and hairy 

 near the base above, attenuate into a slender invo- 

 lute point, the lower elongated, the upper 1'-$' long, 

 setaceous ; panicles $'-2' in length, the terminal one 

 exserted or sometimes partially included, strict, the 

 branches %' long or less, erect, the lateral ones en- 

 closed in the sheaths; spikelets i%"-2%" long, the 

 outer scales unequal, acuminate, smooth, the lower one 

 shorter; third scale scabrous, especially toward the 

 apex, about as long as the second and equalling or 

 slightly exceeded by the very acute palet. 



In dry soil. New York to Illinois and Missouri, south to 

 Georgia and Texas. Aug.-Sept. 



5. Sporobolus neglectus Xash. 



Sheathed Rush-grass. 



Small Rush-grass. (Fig. 345.) 



Sporobolus vaginaeflorus Vasey; A. Gray, Man. Ed. 6, 



645. 1890. Not Wood. 1863. 

 Sporobolus neglectusTSasfa, Bull. Torr. Club, 22: 464. 1895. 



Culms 6'-i2 / tall, erect from a usually decumbent 

 base, slender, often much branched, smooth and 

 glabrous. Sheaths about half as long as the inter- 

 nodes, inflated ; ligule very short ; leaves i" wide or 

 less at the base, smooth and glabrous beneath, sca- 

 brous and hairy near the base above, attenuate into a 

 slender point, the lower elongated, the upper \ f -$ f 

 long, setaceous; terminal panicle \'-2%' in length, 

 usually more or less included in the upper sheath, 

 strict; lateral panicles enclosed in the sheaths; spike- 

 lets about \yt" long, the outer scales acute, the lower 

 one slightly shorter ; third scale acute, glabrous, a 

 little longer than the second and about equalling 

 the acute palet. 



In dry soil, Massachusetts to Kentucky and Kansas. 

 Aug.-Sept. 



