210 NORTH AMERICAN FLORA [VOLUME 17 



XUII. Hemitoma. 

 One species. 



XI/IV- TUERCKHEIMIANA 



One species. 



XLAT. Zizanioidia. 

 One species. 



XIvVI. Gymnocarpa. 

 One species. 



208. P. hemitomon. 



209. P. Tuerckkeimii 



210. P. zizanioides. 



211. P. gymnocarpon. 



1. Panicum distantiflorum A. Rich, in Sagra, Hist. Cuba 11: 304. 



1850. 



Plants cespitose, glabrous; culms 60-80 cm. high, slender, wiry, compressed, producing 

 slender, sometimes fascicled branches from all the nodes; leaf-sheaths longer than the inter- 

 nodes, but narrow and sheathing the joints only at the base, flattened, a minute tuft of hairs 

 on each auricle; ligule a ring of very short hairs; blades erect, firm, narrower than the summit 

 of the sheath, linear to almost capillary, as much as 30 cm. long, 1—2 mm. wide, mostly strongly 

 involute, at least the lower commonly more or less curled, usually with a few hairs at the base; 

 panicles numerous, 2-7 cm. long, very narrow, the branches appressed, scarcely overlapping, 

 the lower 8-15 mm. long, the branchlets bearing 1-3 subsessile spikelets, the setiform pro- 

 longation of the axis rarely equaling the spikelet, usually not more than 1 mm. long ; spikelets 

 1.5 mm. long, 0.7 mm. wide, ellipsoid, acute, glabrous; first glume about half as long as the 

 spikelet, acute, strongly 5-nerved; second glume obtuse, two thirds to three fourths as long 

 as the fruit and the strongly 7-nerved, acute, sterile lemma; fruit 1.3 mm. long, 0,6 mm. 

 wide, elliptic, pointed, finely rugose. 



Type locality: Cuba. 



Distribution: Bahamas, Cuba, and Hispaniola; also in Curacao. 



Illustration: Contr. U. S. Nat. Herb. 15: /. 1. 



2. Panicum utowanaeum Scribn. in Millsp. Field Columb. Mus. 



Publ. Bot. 2: 25. 1900. 



Panicum Sintenisii Nash, Bull. Torrey Club 30: 382. 1903. 



Plants tufted from the nodes of short, slender rootstocks, glabrous; culms ascending or 

 somewhat spreading, 25-60 cm. high, slender, compressed, sparingly branching; leaf-sheaths 



i 



shorter than the internodes, compressed, especially the lowermost, ciliate at the auriculate 

 summit; ligule a minute ring of stiff hairs; blades erect or spreading above, 10-20 cm. long, 

 1-4 mm. wide, slightly scabrous on the margin (sometimes sparsely pilose on the upper surface 

 at the base), narrowed and more or less involute at the base and much narrower than the sheath; 

 panicles 3-10 cm. long, very slender, the scattered, erect branches 1-3 cm. long, the bristle 

 usually equaling or exceeding the spikelet; spikelets subsessile, 2-2.1 mm. long, 0.6-0.7 mm. 

 wide, elliptic, somewhat beaked at the summit, glabrous, pale with green nerves; first glume 

 half as long as the spikelet, acute, 3 -nerved; second glume two thirds to three fourths as long as 

 the fruit, 3-5-nerved, the sterile lemma 5-nerved, abruptly pointed; fruit 1.9 mm. long, 0.6 mm. 

 wide, elliptic, minutely rugose, slightly beaked at the acute apex. 



Type locality: Guanica, Porto Rico. 



Distribution: Cuba, Hispaniola, Porto Rico, and Guadeloupe; also in Venezuela. 



Illustration: Contr. XJ. S. Nat. Herb. 15: /. 2. 



3. Panicum Chapmani Vasey, Bull. Torrey Club 11: 61. 1884. 



Plants cespitose, glabrous; culms ascending or spreading, 40-100 cm. high, slender, 

 compressed, wiry, sparingly branching; leaf -sheaths about as long as the internodes, compressed, 

 pubescent at the scarcely auriculate summit, sometimes ciliate on the margin ; ligule a ring of 

 very short hairs; blades erect, rather firm, linear, 15-40 cm. long, 2-5 mm. wide, acuminate, 

 narrowed to the base, more or less involute when dry, scabrous on the margin and upper sur- 

 face, the latter usually sparsely pilose toward the base; panicles elongate, sometimes as much 

 as 30 cm. long, of remote, appressed, raceme-like branches bearing few to several subsessile, 

 somewhat crowded spikelets, the setiform prolongation of the axis 3-6 mm. long; spikelets 

 2-2.2 mm. long, 1-1.2 mm. wide, obovate, abruptly pointed, turgid, pale-green or yellowish; 



