246 NORTH AMERICAN FLORA [VOLUME 17 



mm, long, 1.2 mm. wide, oblong-obovate, obtuse; first glume one third to two fifths as long 

 as the spikelet; second glume and sterile lemma equal and covering the fruit at maturity, 

 papillose-pilose; fruit 1.8 mm. long, 1.2 mm. wide, ob ovate-elliptic, minutely umbonate. 



Autumnal phase branching at the base, forming soft, spreading tufts, the sheaths over- 

 lapping and the blades but little or not at all reduced, much exceeding the secondary panicles ; 

 spikelets more turgid and obtuse than the primary ones. 



Type locality : North America. 

 Distribution: Georgia to Florida and Alabama. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 144. 



99. Panicum xalapense H. B. K. Nov. Gen. & Sp. 1: 103. 1815. 



Panicum pumilum Bosc; Nees, Agrost, Bras. 228, as synonym. 1829. Not P. pumilum Lam. 

 1798. 



Panicum rariflorum RuDr. ; Galeotti, Bull. Acad. Brux. 9 2 : 240, hyponym. 1842. Not P. rariflorum 



Lam. 1798. 

 Panicum Ruprechti Fourn. Mex. PI. Gram. 21. 1886. Not P. Ruprechtii Fenzl, 1854. 

 Panicum caricifolium Scribn.; Ashe, Jour. Elisha Mitchell Soc. 15: 57, as synonym. 1898. 

 Panicum xalapense strictirameum Hitchc. & Chase, Contr. U. S. Nat. Herb. 15: 161. 1910. 



Vernal phase similar to P. laxiflorum in texture and habit ; culms and leaf -blades on the average 

 shorter, the blades pilose on one or both surfaces or nearly glabrous, usually short-ciliate, the 

 uppermost more or less convolute at base around the culm; panicles hardly so few-flowered; 

 spikelets 1.9-2 mm. long, 1.1 mm. wide, oblong-obovate, obtuse, the first glume one fourth to 

 one third as long as the spikelet ; second glume and sterile lemma pilose, less prominently papil- 

 lose, the glume shorter than the fruit, the latter 1.5 mm. long and 1 mm. wide, oval, minutely 

 umbonate. 



Autumnal phase as in P. laxiflorum, but forming usually denser tufts with shorter leaves. 



Type locality: Jalapa, Vera Cruz. 



Distribution: Maryland to Missouri, and south to Florida. Texas, and Guatemala; Hispaniola. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 4: /. 2; 17: /. 378 (both as P. laxiflorum) ; 

 Contr. U. S. Nat. Herb. 15: /. 146; Britt. & Brown, 111. Fl. /. 262; ed. 2./. 336 (both as P. laxi- 

 florum) . 



Panicum xalapense strictirameum is distinguished by its ovoid, more compact panicles with 

 ascending panicles. It is found from South Carolina to Louisiana. Illustration : Contr. U. S. 

 Nat. Herb. 15:/. 148. 



100. Panicum ciliatum Ell. Bot. S. C. & Ga. 1: 126. 1816. 



Panicum leucoblepharis Trin. Clav. Agrost. 234. 1822. 

 Panicum ciliatifolium Kunth, Rev. Gram. 36. 1829. 

 Panicum ciliatifolium Desv. Opusc. 88. 1831. 



Vernal phase with culms 5-30 cm. high, erect or spreading, sparsely pilose toward the 

 summit, the nodes glabrous; leaf-sheaths ciliate on the margin, otherwise glabrous, usually 

 overlapping; blades 3-6 cm. long, 3-8 mm. wide, the uppermost often much smaller, lanceolate, 

 ciliate on the margin with stiff hairs 2-3 mm. long, arising from papillae; panicles 3-4 cm. long, 

 about as wide, with more numerous spikelets than those of P. xalapense, the branches spreading, 

 flexuous, the axis pilose; spikelets 1.8-2 mm. long, 1 mm. wide, ob ovate-elliptic; first glume 

 half the length of the spikelet, subacute; second glume and sterile lemma equal, not exceeding 

 the fruit, villous; fruit 1.7-1.8 mm. long, 0.9 mm. wide, elliptic, the apex minutely umbonate. 



Autumnal phase in flat, soft mats, similar to those of P. xalapense. 



Tvpb locality: South Carolina. 



Distribution: North Carolina to Florida and Louisiana. 



Illustrations: Bull. U. V S. Dep. Agr. Agrost. 4: /. 8; 17: /. 379; Contr. U. S. Nat. Herb. 

 15: /. 150; Britt. & Brown, 111. FL ed. 2./. 334. 



101. Panicum polycaulon Nash, Bull. Torrey Club 24: 200. 1897. 



Panicum dichotomum glabrescens Grriseb. Fl. Brit. W. Ind. 553. 1864. 



Vernal phase similar to that of P. ciliatum; culms rarely more than 20 cm. high, glabrous, 

 but pilose in the long-exserted panicle; leaf -sheaths sparingly ciliate; blades on the average 

 narrower than those of P. ciliatum; spikelets 1.5-1.6 mm. long (exceptionally as much as 2 mm. 

 long), 0.8 mm. wide, obovate, blunt, glabrous; first glume one third to half the length of the 

 spikelet, subacute; second glume and sterile lemma strongly nerved; fruit 1.4 mm. long, 0.8 

 mm. wide, elliptic, subacute, not umbonate. 



Autumnal phase in flat, soft mats, similar to those of P. xalapense, but smaller. 



Type locality: Tampa, Florida. 



Distribution : Florida to southern Mississippi and the Greater Antilles. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 17: /. 380; Contr. U. S. Nat. Herb. IS: /. 152. 



