519 
long, lacerate: panicle loosely subspicate or interrupted, 1 to1.5 din. long: spikelets 3 
to 3.5 mm, long; empty glumes obtuse, nerveless, subequal, one-half as long as the 
floret; floral glume obscurely 3 to 5-nerved, subobtuse.—Limpia canon, Presidio 
County, Texas. 
++ ++ Panicles terminal and lateral, mostly inclosed in the sheaths. 
= Culms rather robust: panicles 1 dm. long or more. 
4. S. asper (Michx.) Kth. (PRamiE Grass.) Culms erect, mostly simple, 5 to 10 
dm, high: lower leaves 2 to 4 dm, long, tapering to an involute point; culm leaves 
shorter, the upper ones with a broadly inflated sheath partly or wholly inclosing 
the panicle: terminal panicle 1 to 2 dm, long, slender: spikelets 4 to 6 mm, long; 
empty glumes acute, unequal, one-half to three-fourths as long as the one-nerved 
acute floral glume and broad palet: grain nearly 2mm.long. (Agrostis asper Michx.)— 
Dry land, Texas, and northward. Var. DruMMONDI Vasey has the terminal panicle 
usually exserted, empty glumes nearly equal and little more than one-half as long as 
the floret, and palet nearly one-fourth shorter than the glume.—Rich low land, 
Texas, and northward. 
Novre.—Two varieties of 8. eryptandrus may be looked for here. 
— = Culms slender: panicles 5 cm. long or less. 
5. S. vagineeflorus (Torr.) Vasey. (SOUTHERN POVERTY Grass.) Culms tufted, 
usually geniculate, 2 to 5 din. high: leaves closely involute, mostly less than 1 dm. 
long: panicles 2 to 4 cm. long, usually one for each internode, inclosed in the 
inflated sheaths: spikelets 2 to3.mm, long; empty glumes acute, subequal, nearly as 
long as the floret: grain more than one half as long as the equal glume and palet. 
(Vilfa vagineflorus Torr.)—Dry sterile soil, northern Texas and eastward. 
6. S. filiculmisnom.noy. Culms3to6dm., high, very slender, weak, tufted, usually 
geniculate, branching: leaves short, closely involute: panicles mostly terminal, and 
at length exserted, 2 to 4 cm. long, slender: spikelets about 4 mm. long; empty 
glumes, floral glume and palet all nearly equal, narrow and acute. (Sporobolus minor 
Vasey in Gray Man, 646, 1891, non Kunth 1833.)—Dry, sterile soil, northern Texas and 
eastward, 
~ + Culms low and decumbent, from crecping rootstocks, 
7. S$. depauperatus (Torr.) Vasey. (APAREJOS Grass.) Culms decumbent and 
much branched in a tangled prostrate mat, with ascending branches Ll to 3 dm, high: 
leaves 1 to 3 dm. long, mostly involute and curved ; sheaths exceeding the inter- 
nodes: panicle 2 to 5 cm. long, somewhat interrupted: spikelets about 2.5 mm. long; 
empty glumes broad, abruptly acute, about one-half as long as the 3-nerved acute 
or submucronate floral glume; palet nearly as long as the glume, (Vilfa depauperata 
Torr. )—Dry gravelly soil, western Texas to California. 
8. §. Sacatilla Griseb. (Sacatirna.) Culms much branched, 1 to 2 dm. high, 
very slender, ascending from a strong rootstock: leaves numerous, almost filiform- 
involute, divergent or recurved; sheaths exceeding the short internodes: terminal 
panicles about 2 cm. long, lateral ones shorter, interrupted: spikelets 2 to 3 mm. 
long; empty glumes obtuse, one-half as long as the equal acute floral glume and 
? 
palet.—Dry mountain sides, western Texas. 
+ « Panicle spreading except in two varicties of No. 18, 
+ Spikelets somewhat crowded, short pedicelled and loosely appressed along the branches 
or short subdivisions except in S. cryptandrus var. flexuosus ; first empty glume not 
more than one-half as long as the second. 
+ Culms short: panicle less than 5 cm, long. 
