Part 3, 1915] POACEAE) 



261 



the base and margins, the lower surface densely vel vety-villous ; panicles short-exserted, 7-11 

 cm. long, nearly as wide, rather densely flowered, the axis sparingly villous near the base, the 

 branches spreading; spikelets 2 mm. long, 1 mm. wide, elliptic, somewhat obovate at maturity, 

 obtuse, pubescent with soft, spreading hairs; first glume one fifth the length of the spikelet, 

 obtuse or obscurely pointed; second glume and sterile lemma equal, scarcely equaling the fruit 

 at maturity, obtuse or slightly pointed; fruit 1.7 mm. long, 1 mm. wide, elliptic, subacute. 



Autumnal form erect, after the maturity of the primary panicle bearing at the middle 

 nodes a few appressed or ascending fascicled branches scarcely longer than the primary in- 

 ternodes, the reduced blades flat or somewhat involute at the tips, ciliate. 



Type locality: Waller County, Texas. 

 Distribution : Southern Alabama to eastern Texas 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 232. 



142. Panicum olivaceum Hitchc. & Chase, Contr. U. S. Nat. Herb. 



15: 225. 1910. 



Vernal culms olive- green, erect or somewhat spreading at base, 20-40 cm. high, velvety- 

 villous with short hairs, the nodes bearded ; leaf -sheaths villous like the culm, mostly shorter 

 than the internodes; ligule 3-4 mm. long; blades rather stiffly erect or ascending or some of the 

 lower spreading, 4-7 cm. long, 5-8 mm. wide (the uppermost erect, 1-3 cm. long), puberulent 

 on both surfaces, also more or less short-villous above, and often with longer villous hairs toward 

 the base; panicles 3-7 cm. long, ovate, the flexuous branches spreading, with short spikelet- 

 bearing branchlets in the axils; spikelets 1.9-2 mm. long, 1 mm. wide, obovate, subacute, 

 papillose-pilose ; first glume one fourth to one third the length of the spikelet, usually pointed ; 

 second glume scarcely equaling the fruit and sterile lemma; fruit 1.6 mm. long, 1 mm. wide, 

 subacute. 



■ 



Autumnal phase upright or becoming decumbent-spreading, freely branching from the 

 lower and middle nodes before the maturity of the primary panicle, the reduced branches 

 appressed, or in the decumbent culms curved upward ; blades reduced, flat, 1-2 cm. long, 2-4 

 mm. wide, usually conspicuously ciliate. 



Type locality: Coban, Guatemala. 

 Distribution: Mexico to Venezuela. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 234. 



143. Panicum praecocius Hitchc. & Chase; Hitchc. Rhodora 



8: 206. 1906. 



Vernal culms tufted, 15-25 cm. high, early branching and elongating, sometimes to 45 cm., 

 at first erect, soon becoming geniculate and spreading, very slender, wiry, abundantly papil- 

 lose-pilose with weak spreading hairs 3-4 mm. long; leaf -sheaths, even the lowest, much shorter 

 than the very long internodes, those of the branches usually but 1-2 cm. long, pilose like the 

 culm, more prominently papillose; ligule 3-4 mm. long; blades rather firm, erect or ascending, 

 5-9 cm. long, 4-6 mm. wide, the margins parallel about two thirds their length, acuminate, 

 long-pilose on both surfaces, the hairs of the upper surface 4^5 mm. long, erect from the plane 

 of the blade, the under surface prominently papillose; panicles at first usually overtopped by 

 the upper leaf, but at or past maturity exserted, 4-6 cm. long, about as wide, loosely flowered, 

 the axis pilose, the branches flexuous, spreading or ascending; spikelets 1.8-1.9 mm. long, 1 mm. 

 wide, obovate, turgid, obtuse, pilose; first glume one third to half the length of the spikelet, 

 .triangular ; second glume and sterile lemma subequal, the glume slightly shorter than the fruit 

 at maturity; fruit 1.6 mm. long, 1 mm. wide, broadly elliptic. 



Autumnal phase ascending from a geniculate base, or in prairie sod erect, forming close 

 bunches 10-20 cm. high, the upper portion of the primary culms early deciduous, the branches 

 appressed, the scarcely reduced blades erect or narrowly ascending, much exceeding the re- 

 duced panicles; winter rosette appearing late, the blades 2-3 cm. long, long-pilose. 



Type locality: Wady Petra, Illinois. 



Distribution: Michigan to Minnesota and eastern Texas. 



Illustrations: Contr. U. S. Nat. Herb. 15: /. 235; Britt. & Brown, 111. Fl. ed. 2./. 360. 



