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1. M. diffusa Pursh. Culms about 1 m. high, simple: leaves nearly 1 cm. broad: 
panicle 1 to 2 dm. long; branches mostly in twos with the spikelets racemose and 
pendant: spikelets 10 to 12 mm. long, usually 2-flowered; first empty glume very 
broad, membranaceous, shorter than the obovate second; floral glume lance-oblong, 
membranaceous at the obtuse apex: grain spindle-shaped, about 2.5 mm, long.— 
Rocky ravines, central Texas to Arkansas and westward to New Mexico. 
2. M. mutica Walt. Culms 4 to 8 dm. high: leaves 3 to 7 mm. wide: panicle 1 to 
1.5 dm. long, with few spreading branches or sometimes reduced to a simple raceme: 
spikelets pendant, 8 to 10 mm. long, 2-flowered; empty glumes subequal, subacute, 
the lower broader, nearly equaling the florets. —Moist land, central Texas to Georgia 
and Maryland. 
** Spikelets conical or narrowly linear: rudiment narrowly conical or linear: rachilla not 
prominently elongated: floral glume 4 to 7-nerved, 
8. M. Porteri Scribu. Culms 5 to 8 dm. high: leaves narrow, 2 to 4 dm. long: 
panicle narrow, 2 to 3dm, long: spikelets racemose, pendant on the few slender 
branches, 8 to 12 mm, long, 2 to 4-flowered; empty glumes equal, about one-third 
shorter than the lower floret: grain oblong, subacute, 2,5 mm. long.—Mountains, 
Texas to Arizona and adjacent Mexico. 
4. M. multinervosa Vasey. Culms slender, 5 to 10 dm. high: leaves slender, often 
involute; lower sheaths pubescent at the base: panicles 1 to 1.5 dm, long; branches 
few, nearly erect or the lower ones spreading: spikelets rigid, 8 to 12-flowered, 1 to 
2em. long; empty glumes ovate, acute, coriaceous; floral glume, coriaceous, pubes- 
cent at the base: grain 2.5 mm. long, obovate with a broad, deep channel.—Rare, 
southern Texas. Apparently diccious but the staminate form not seen. In many 
respects this species appears to be more closely related to Sieglingia Wrightit than 
to any of the Melicas. 
64. UNIOLA L. 
Spikelets with 3 to 15 perfect florets and 3 to 9 empty glumes at the 
base and usually one or two imperfect florets at the apex, compressed, 
awnless: panicle narrow or somewhat spreading: floral glumes rather 
rigid, acute or denticulate, 7 to 15-nerved, one-half to one-third longer 
than the palet: grain flattened, obtuse, smooth.—Mostly tall grasses 
with simple leafy culms, tufted from perennial rootstocks. 
* Spikelets large, in ample panicles : floral glumes prominently keeled. 
1. U. paniculata L. (Sea oats.) Culm 1 to 3 dm. high, coarse: leaves involute, 
long attenuate: panicle rather dense, 8 t05 dm. long: spikelets short pedicelled, 
1 to 3 dm. long, flatly compressed, with 5 to 15 perfect florets and two or three pairs 
of empty glumes nearly as long as the mucronate or denticulate floral glumes,— 
Drifting sand along the coast, southern Texas to New Jersey. 
2. U. latifolia Michx. (BROAD-LEAVED SPIKE-GRass.) Culms nearly 1 m, high: 
leaves numerous, nearly 2 em, wide: panicle spreading, rather loose: spikelets 2 to 
4 cm. long and more or Jess drooping on the long pedicels, flatly compressed ; usually 
4 empty glumes, the upper pair slightly shorter than the prominently carinate acute 
Sandy river banks, central Texas to Illinois and eastward. 
floral glume. 
* * Snikelets small, in narrow panicles : floral glumes conver, acuminate. 
3. U. gracilis Michx. (SLENDER SPIKE-GRASS. ) Culms slender, 6 to 10 dm. high: 
leaves narrow: panicle very slender, sometimes simple, 2 to 5 dm. long: spikelets 5 
to 8 mm. long, with 3 to 5 perfect florets, the three lower glumes empty and short; 
florets turgid, the glumes involute acuminate at the beak-like points.—Wet wood- 
land, central Texas to Florida and Pennsylvania. 
