152 GRAMINEAE. 
3. Sporobolus pildsus Vasey. Hairy Rush-grass. (Fig. 343.) 
Sporobolus pilosus Vasey, Coult. Bot. Gaz. 16: 26. 1891. 
Culms 1°-1%° 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, 
1//-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/-3/ in length, included at the base, erect, strict, 
its branches %/-1’ long, erect; spikelets 2'4’’ 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. Sheathed Rush-grass. 
(Fig. 344.) 
Vilfa vaginaeflora 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 8/-18’ tall, erect, slender, smooth or scabrous. 
Sheaths usually inflated, about half as long as the 
internodes; ligule very short; leaves 1’’ 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/-3’ long, 
setaceous ; panicles 3//-2’ in length, the terminal one 
exserted or sometimes partially included, strict, the 
branches 1%4/ long or less, erect, the lateral ones en- 
closed in the sheaths; spikelets 13///-244’’ 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 negléctus Nash. Small Rush-grass. (Fig. 345.) 
Sporobolus vaginaeflorus Vasey; A. Gray, Man. Ed. 6, 
645. 1890. Not Wood. 1863. 
Sporobolus neglectus Nash, Bull. Torr. Club, 22: 464. 1895. 
Culms 6/-12/ 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 1/’ 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 1/—3/ 
long, setaceous; terminal panicle 1/-214’ in length, 
usually more or less included in the upper sheath, 
strict; lateral panicles enclosed in the sheaths; spike- 
lets about 114’ 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. 
