Part 3, 1915] POACEAE 231 



58. Panicum longifolium Torr. FL U. S. 149. 1824. 



Panicum anceps pubescens Vasey, Bull. U. S. Dep. Agr. Bot. 8: 37. 1889. 

 Panicum pseudanceps Nash, Bull. Torrey Club 25: 85. 1898. 



Plants in dense tufts, 35-80 cm. high, usually surrounded by basal leaves nearly half as 

 long as the culm; culms rather slender, much compressed, stiff, glabrous ; .leaf -sheaths mostly 

 shorter than the internodes except at the base, keeled, usually hairy" on the sides at the juncture 

 with the blade, otherwise glabrous or villous toward the summit, sometimes densely so; ligule 

 fimbriate-ciliate, 2-3 mm. long, the cilia usually at the sides only, not meeting at the back; 

 blades erect or sometimes recurved or tortuous, conduplicate at base, flat above or somewhat 

 involute, 8-40 cm. long, 2-5 mm. wide, pilose on the upper surface toward the base, sometimes 

 also on the lower surface ; lateral panicles few or none ; terminal panicles finally long-exserted, 

 much exceeding the leaves, 10-25 cm. long, usually half to two thirds as wide, but sometimes 

 rather contracted, the distant, slender branches solitary or fascicled, ascending, usually naked 

 at base, bearing short, appressed, rather closely flowered branchlets, these and the pedicels 

 scabrous, the latter sometimes with a few hairs at the summit; spikelets 2.4—2.7 mm. long, 

 about 0.7 mm. wide; first glume two fifths to scarcely half the length of the spikelet, acute; 

 second glume slightly longer than the sterile lemma, both keeled, usually spreading at the tip, 

 scabrous on the midnerve at the apex; fruit 1.6 mm. long, 0.6 mm. wide. 



Type locality: New Jersey. 



Distribution: Rhode Island to Florida and Texas. 



Illustrations: Contr. U. S. Nat. Herb. 15: /. 98; Ann. Rep. N. J. Mus. 1910: pi. 7, /. 5; 

 Britt. & Brown, 111. Fl. /. 251; ed. 2. /. 327. 



59. Panicum Combsii Scribn. & Ball, Bull. U. S. Dep. Agr. Agi;ost. 



24: 42. 1901. 



Plants like P. longifolium in habit; leaves somewhat more clustered at base; leaf -sheaths 

 glabrous or pubescent along the margin toward the summit; ligule less than 1 mm. long, some- 

 times a few longer hairs at the margin; blades averaging shorter, rarely 25 cm. long, glabrous 

 or pilose on the upper surface at the base, usually sparsely so ; lateral panicles wanting or but 

 one or two; terminal panicles 12-20 cm. long, two thirds to three fourths as wide, few-flowered, 

 the slender, scattered branches ascending; spikelets 3-3.5 mm. long, 0.7-0.8 mm. wide, acumi- 

 nate ; first glume two thirds to three fourths the length of the spikelet ; second glume and sterile 

 lemma subequal, usually scabrous on the midnerve, much exceeding the fruit; fruit 1.8-2 mm. 

 long, 0.6-0.8 mm. wide. 



Type locality: Chipley, Florida. 



Distribution: Southern Georgia and northern Florida to Louisiana. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 24: /. 16; Contr. U. S. Nat. Herb. 15: /. 100. 



60. Panicum anceps Michx. Fl. Bor. Am. 1: 48. 1803. 



?Panicum pennsylvanicum Spreng. Bot. Gart. Halle Nachtr. 1: 30. 1801. 



Panicum rostratum Muhl.; Willd. Enum. 1032. 1809. 



Agrostis nutans Poir. in Lam. Encyc. Suppl. 1: 255. 1810. 



Panicum nutans Desv. Opusc. 93. 1831. 



Panicum anceps angustum Vasey, Bull. U. S. Dep. Agr. Bot. 8: 37. iy °9. 



Panicum anceps densiflorum Vasey, Bull. U. S. Dep. Agr. Bot. 8: 37. 1889. 



Plants in tufts of few to many culms, 50-100 cm. high or more, with numerous stout, 

 scaly rootstocks ; culms usually robust, not strongly compressed, glabrous ; leaf -sheaths usually 

 shorter than the internodes, glabrous to densely papillose-pilose, especially at the summit; 

 ligule membranaceous, less than 1 mm. long; blades erect, flat or but slightly conduplicate at 

 base, 20-50 cm. long, 4-12 mm. wide, pilose and usually ciliate on the upper surface toward the 

 base] otherwise glabrous, scabrous or more or less pubescent on the upper and occasionally on 

 the under surface: panicles terminal only, or narrow, long-peduncled panicles produced from 

 the upper sheaths, the terminal ones finally long-exserted but often nearly equaled by the long 

 blades, 15-40 cm. long, usually half to two thirds as wide (or occasionally narrow), the long, 

 slender, remote branches somewhat spreading, bearing short, mostly appressed, distant or 

 approximate branchlets with rather crowded, somewhat curved, subsecund spikelets set ob- 

 liquely on their short, appressed, scabrous pedicels, the first glume toward the main axis, the axis 

 and branches scabrous, usually with a few hairs in the axils; spikelets 3.4-3.8 mm. long, 1-1.2 



