HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



321 



Kentucky: Irvine, Biltmore Herb. 9959f (Biltmore Herb.). 



Tennessee: Knoxville, Ruth 70, Scribner in 1892; Madison County, Bain 189. 



Alabama: Auburn, Hitchcock 1321. 



Mississippi: Fairport, Tracy 3205; Jackson, Hitchcock 1301; Starkville, Tracy in 



Pollard Dist. Miss. PL 1409. 

 Arkansas: Benton County, Plank 16, 46. 

 Louisiana: Covington, Langlois 41 in part; Calhoun, Hitchcock 1283. 



MISCELLANEOUS SPECIES. 

 192. Panicum obtusum H. B. K. 



Panicum obtusum H. B. K. Nov. Gen. & Sp. 1: 98. 1815.. "Crescit in planitie 

 montana regni Mexicani prope Guanaxuato et Burras, in humidis, alt. 1080 hexap." 

 The type specimen, in the Bonpland Herbarium, is labeled: "Panicum obtusum 

 Kunth, Synops. 174, in planitie montana Regni Mexicani, prope Guanaxuato, 1080 

 hex. No. 4204." 



Panicum polygonoides C. Muell. Bot. Zeit. 19: 323. 1861. "America septentrio- 

 nalis, ubi forsan in Texas legit T. Drummond (Coll. No. 371)." The type specimen, 

 bearing the published data, is in the Berlin Herbarium. 



Panicum repente Buckl. Prel. Rep. Geol. Agr. Surv. Tex. App. 3. 1866. No speci- 

 men nor locality within Texas is cited. The type specimen. could not be found in 

 the herbarium of the Philadelphia Academy, where the Buckley collections are 

 deposited. The description amply identifies the species. 



Brachiaria obtusa Nash in Britton, Man. 77. 1901. Based on Panicum obtusum 

 H. B. K. In this species the spikelets are placed with the back of the fruit to the 

 axis (that is the first glume turned from the axis) as characteristic of true Panicum, 

 not in the reverse position which characterizes Brachiaria.^ 



description. 



Plants perennial, usually tufted from a more or less knotted rootstock, and produc- 

 ing widely creeping stolons, sometimes 2 or more meters long, with long internodes, 

 and geniculate, swollen, conspicuously villous nodes, these often with a knob-like 

 cluster of hairy scales at the base of the extra- 

 vaginal, erect branches, these clusters being pro- 

 duced sometimes when the branch is not developed; 

 culms wiry, compressed, 20 to 80 cm. high, simple, 

 usually decumbent at base, glabrous, the nodes 

 glabrous; sheaths shorter than the internodes, glab- 

 rous, or the lower and those of the stolons some- 

 times villous; ligules membranaceous, about 1 mm. 

 long; blades 3 to 20 cm. long, 2 to 7 mm. wide, erect, 

 firm, usually involute-setaceous toward the tip, 

 glabrous on both surfaces or sometimes with a few 

 long hairs on the upper surface at the base; pani- 

 cle usually short-exserted, 3 to 12 cm. long, about 1 

 cm. wide, the few, appressed, raceme-like branches 

 densely flowered; spikelets short-pediceled along 

 one side of a slightly flattened rachis, 3 to 3.8 mm. long, 1.5 to 1.8 mm. wide, and 

 about 2 mm. thick, obovoid, blunt, glabrous, usually brownish; first glume nearly 



. » The genus Brachiaria Ledeb. (Fl. Ross. 4: 469. 1853) is based upon Panicum 

 eruciformis Sibth., in which the spikelets are placed with the back of the fruit turned 

 from the rachis. 



Fig. 361.— P. ohtusum. From type 

 specimen. 



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