244 NORTH AMERICAN FLORA [Voujmk 17 



sparsely hirsute, the stiff hairs irregularly distributed ; first glume about two thirds the length 



of the spikelets, acuminate ; second glume and sterile lemma subequal, exceeding the fruit, 



abruptly pointed, the latter subtending a palea and staminate flower; fruit 2.1 mm. long, 1.1 



mm. wide, elliptic, smooth and shining, a cartilaginous flap-like appendage at the base. 



Type locality: Guiana. 



Distribution: Jamaica; Costa Rica to Brazil. 



Illustrations: Rudge, PI. Guian. 1: pi. 29; Contr. U. S. Nat. Herb. 15: /. 133. 



93. Panicum megiston Schultes, in R. & S. Syst. Veg. Mant. 2: 248. 



1824. 



Panicum altissimum G. Meyer, Fl. Esseq. 63. 1818. Not P. altissimum DC. 1817. 



Panicum elatius Kunth, R6v. Gram. 38. 1829. 



Panicum tuberculatum J. Presl, in Presl, Rel. Haenk. 1: 307. 1830. 



Panicum Equisetum Nees; Doell, in Mart. Fl. Bras. 2 2 : 206, as synonym. 1877. 



Plants perennial ; culms tall and robust, glabrous ; leaf -sheaths papillose-hispid or papillose 

 only; ligule fimbriate, about 1.5 mm. long; blades firm, ascending, 15-40 cm. long or more, 1.5-3 

 cm. wide, linear-lanceolate, slightly narrowed to the rounded base, glabrous; panicles finally 

 exserted, 40-60 cm. long, the stiff main axis striate-angled, smooth or scabrous, the branches 

 in distant verticils, often as many as 20-30 in a verticil, 10-20 cm. long, slender, stiffly or sinu- 

 ously ascending, very scabrous, nearly simple, bearing the scattered, short-pediceled spikelets 

 along the upper half or third; spikelets usually purplish at maturity, about 3.4 mm. long, 1.5 

 mm. wide, globular-obovoid, glabrous; first glume scarcely one third the length of the spikelet, 

 pointed ; second glume slightly shorter than the sterile lemma, both abruptly apiculate, 7-9- 

 nerved, the glume about equaling the fruit, the sterile palea rather firm, about as long as the 

 fruit; fruit 2.8 mm. long, 1.4 mm. wide, abruptly pointed, smooth and shining. 



Type locality: British Guiana. 

 Distribution: Cuba; Mexico to Paraguay. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 135. 



94. Panicum depauperatum Muhl. Descr. Gram. 112. 1817. 



Panicum strictum Pursh, Fl. Am. Sept. 69. 1814. Not P. strictum R. Br. 1810. 



Panicum rectum R. & S. Syst. Veg. 2: 457. 1817. 



Panicum involutum Torr. Fl. U. S. 144. 1823. 



Panicum Muhlenbergii Spreng. Syst. 1: 314. 1825. 



Panicum junceum Trin. Gram. Pan. 220. 1826. 



Panicum Sprengelii Kunth, Rev. Gram. 39. 1829. 



Panicum depauperatum involutum Wood, Class Book ed. 1861. 786. 1861. 



Panicum depauperatum laxum Vasey, Bull. U. S. Dep. Agr. Bot. 8: 29. 1889. 



Vernal phase with culms several to many in a tuft, 20-40 cm. high, slender but rather stiff, 

 erect or spreading at the summit, glabrous, puberulent or sometimes pilose; nodes ascending- 

 pubescent; leaf-sheaths, except the lowest, shorter than the internodes, glabrous to papillose- 

 pilose; blades linear, 6-15 cm. long, 2-5 mm. wide (the lower shorter), often involute in drying, 

 scabrous on both surfaces, sometimes pubescent beneath; panicles exserted, usually not much 

 exceeding the leaves, 4-8 cm. long, rarely longer, few-flowered, the rather strict, remote branches 

 narrowly ascending at maturity; spikelets 3.2-3.8 mm. long, rarely only 3 mm. or as much as 

 4 mm. long, 1.5-1.7 mm. wide, elliptic, pointed, glabrous or sparsely pubescent; first glume 

 one third to half the length of the spikelet, subacute; second glume and sterile lemma equal, 

 extending beyond the fruit, forming a beak, strongly 7-9-nerved; fruit 2.1-2.3 mm. long, 1.4-1.5 

 mm. wide, oval, minutely umbonate at the apex. 



Autumnal phase similar to the vernal, the reduced secondary panicles produced on branches 

 from the basal or lower nodes, more or less concealed in the tuft of basal leaves. 



Type locality: Pennsylvania. 



Distribution: Maine to Minnesota, and south to Georgia and Texas. 



Illustrations: Bull. Tenn. Exp. Sta. 7: pi. 13, f. 49; Bull. U. S. Dep, Agr. Agrost. 17: /. 

 385; Contr. U. S. Nat. Herb. 15: /. 136; Britt. & Brown, 111; Fl. /. 268; ed. 2. /. 329. 



95. Panicum perlongum Nash, Bull. Torrey Club 26: 575. 1899. 



A- 



Panicum Pammeli Ashe, Bull. N. Car. Exp. Sta. 175: 116. 1900. 



Vernal phase similar to that of P. depauperatum, more strict in habit, and in smaller tufts, 

 more constantly pilose and usually papillose, the blades on the average longer and narrower, 



