15 



the typical material only in having the panicle pale instead of purple, or at 



least only the spikelets being tipped with purple. 

 4. CHiETOCHLOA GRACILIS (H. B. K.) n. comb. Setaria gracilis H. B. K. 



Nov. Gen. & Sp. PI. 1 : 109 (1815) . Setaria imberhis R. & S. of authors. (Fig. 4.) 

 A slender, erect, glabrous, caespitose perennial, 3 to 7 dm. high, from short, creeping 



rootstocks, with linear-setaceous leaves, very slender, spike-like panicles 2 to 6 



cm. in length, and short setse, often barely exceeding the spikelets. Culms very 



slender, erect, glabrous, cylindrical, simple or somewhat branched at the base; 



nodes glabrous; sheaths loose, 



glabrous, shorter than the inter- 

 nodes, not ciliate on the hyaline 



margins; ligule very short, cili- 

 ate; leaf -blades involute-seta- 

 ceous, 0.5 to 2 dm. long, 1 to 3 mm. 



wide, smooth or slightly scabrous 



above, long-acuminate. Panicles 



cylindrical, dense, 3 to 5 mm. in 



diameter, branches contiguous, 



very short, 1-fiowered; rachis 



setose or pubescent; seta? 5 to 8, 



involucrate, unequal, very short, 



flexuous, equaling or twice ex- 

 ceeding the spikelet,- yellowish, 



antrorsely scabrous. Spikelets 



2 mm. long, ovate, acute; first 



glume triangular-ovate, acute, 3- 



nerved, one-third the spikelet in 



length; second glume one-half as 



long as the spikelet, ovate, acute, 



5-nerved; third glimie equaling 



the flowering glume, 5-nerved, 



sulcate, subtending a broad- 

 ovate, hyaline palea its own 



length; flowering glume ovate, 



acute, abruptly apiculate, trans- 

 versely undulate-rugose. Palea 



plane, striate. 

 Alaliama, Florida, Texas, Mexico to 



South America. 

 Specimens examined. — Alabama : 



Mobile, on "ballast" and about 



wharves, 14 Mohr 1891; 19 



Kearney 1895. Florida: Apala- 



chicola, on "ballast," Chapman, 



no date. Texas: No locality, 



Buckley 1888; Nealley 1887, 1888; 



Corpus" Christi, Nealley 1891. 



Cuba: 3473 Wright 1860-64 ; Reed, 



no date. Mexico: Cordova, 5 Fink 1889-1891; Chihuahua, Palmer 1885; Oaxaca 



1907, Nelson 1894. 



B. Setx 1-3, not involucrate. 



* Panicle dense cylindrical; branches short, appro.rimaie. 



■\8etx retrorsely scabrous, tvholly or in jxirt. 



5. CHiETOCHLOA BREVISPICA nom. nov. Panicum veriicillatuin parvljtomm 

 Doell iu Mart. Fl. Bras. 2': 172. (1877), not Cenchrus parviflorus Poir. in Lam. 

 Encycl. 6: 52 (1804.). (Fig. 5.) 



Fig. 5.—Chcetoehloa brevispiea: a, branch showing 

 spikelets audsette; 6, spikelet allowing the first and 

 third glumes ; c, flowering glume seen from the back; 

 d, anterior view of the flowering glume, showing 

 palea. 



