HITCHCOCK AND CHASE NORTH AMERICAN PANICUM. 109 



tiss 5936; Apalachicola, Biltmore Herb. Dist. Dupl. Chapman 696b; Monti- 

 cello, Combs 320; Homosassa, Combs 935, 972; Lake City, Chase 4284; Crystal, 

 Combs 102X>; Gainesville, Chase 4201, Combs 717; Old Town, Combs 878 

 Chipley, Combs 560, 586; Grasmere, Combs 1073; Orange Bend, Chase 4095 

 Bartow, Combs 1206; Tampa, Combs 1398; Fort Lauderdale, Eaton 341 

 without locality, Chapman. 



Kentucky: Bell County, Kearney 372 in part. 



Tennessee: Bristol, Hitchcock 229; Lavergne, Biltmore Herb. 696a; Knoxville, 

 Ruth in 1895 and 1898; Cocke County, Kearney 965; Grainger County, Smith 

 in 1880. 



Alabama: Auburn, Tracy in 1897; Birmingham, McCarthy in 1888; Gadsden, 

 McCarthy in 1888; Nesheka, Carver 7; Cullman, J/o/?r in 1885. 



Mississippi: Nicholson, -Kearney 376; Taylorville, Tracy 8414; Waynesboro, Pollard 

 1228; Tupelo, Tracy 1535; Starkville, CTjase 4464, Kearney 20 in part; Biloxi, 

 Tracy 4620 and in 1893; Bay St. Louis, Langlois in 1883, ; Pass Christian, 

 Langlois in 1882. 



Arkansas : Benton County, Plank 65 ; Miller County, Eggert in 1896 ; Harvey in 1880, 



Louisiana: Natchitoches, Ball 166; Kayville, Ball 8; Coushatta County, Ball 125; 

 Calhoun, Ball 46; Oberlin, 5aZZ 228; West Carroll Parish, Moseley in 1903; 

 Lake Charles, Chase 4393; Calcasieu, Cocks 3001. 



Texas: Texarkana, Heller 4082, Plank 80; Columbia, Pwsft 1298; Rusk, Plank 76; 

 Beaumont, PZcm£ 25; Marshall, Riggs 91; Waller, Thurow in 1898; Ennis, 

 £?m7A in 1897; Industry, Wurzlow in 1894; without locality, Nealley in 1887; 

 Reverchon 106. 



Oklahoma: On the False Washita, Palmer 380 in 1868; Kingfisher County, 

 Carleton in 1891; Choctaw Agency, Bigelow in 1853-4. 



56. Panicum rhizomatum sp. nov. 



DESCRIPTION. 



Plants like P. anceps in habit; the culms less robust, the scaly rhizomes slender and 

 more numerous; leaves more or less clustered toward the base, the sheaths, except the 

 lowermost, shorter than the internodes, densely to sparsely 

 villous along the margin, and toward the summit, a dense 

 ring of pubescence at the juncture with the blade; ligules 

 nearly obsolete; blades erect or the lower commonly spread- 

 ing, 10 to 40 cm. long (usually not over 30 cm.), 5 to 10 mm. 

 wide, pubescent on both surfaces or sometimes glabrous 

 except on the upper surface toward the base; terminal 

 panicles long-exserted, the usually numerous smaller ax- 

 illary ones short-peduncled or partially included, 10 to 25 

 Fig. 104.— P. rhizomatum. cm - l° n g> usually less than one-third as wide, more or less 

 From type specimen. contracted and densely flowered, rather more compound 

 than in P. anceps, the distant primary branches ascend- 

 ing, bearing numerous branchlets 1 to 3 cm. long, these with appressed, short, 

 approximate branchlets, with crowded spikelets set obliquely on their short, 

 appressed pedicles as in P. anceps, but hardly at all secund; spikelets 2.4 to 2.8 mm. 

 long, about 1 mm. wide; first glume one-third to scarcely half as long as the spikelet, 

 acute; second glume and sterile lemma subequal, beaked as in P. anceps but less 

 strongly so, but little exceeding the fruit; fruit 1.9 mm. long, 0.9 mm. wide. 



Type U. S. National Herbarium no. 592752, collected August 18, 1905, Orangeburg, 

 S. C, by A. S. Hitchcock (no. 450). 



This species was referred by Scribner in the herbarium to P. anceps pubescens Vasey 

 and was distributed under this name by Nash and others. It is distinguished from 

 P. anceps by the somewhat contracted, more densely flowered panicles of smaller 



