224 



CONTEIBUTIONS FROM THE NATIONAL HERBARIUM. 



^J^^ 



surface velvety with copious long, silky hairs intermixed, especially toward the base, the 

 lower surface silky-villous or velvety, the nerves somewhat conspicuous ; panicles short- 

 exserted, 3 to 5 cm. long, about as wide, the axis velvety, with long, silky hairs inter- 

 mixed, the flexuous branches ascending or spreading; spikelets 1.3 to 1.4 mm. long, 

 0.8 to 0.9 mm. wide, obovate, very turgid, densely papillose-pubescent; first glume 

 one-third to half the length of the spikelet, acute; second glume and sterile lemma 

 equal and covering the fruit at maturity; fruit 1.1 to 1.2 mm. long, 0.8 mm. wide, 

 obovate-elliptic, minutely pointed. 



Autumnal form early becoming diffusely branched at all the nodes, prostrate- 

 spreading, forming large mats, the branches curved upward at the ends; earlier branches 

 longer than the primary internodes, the ultimate branchlets in short fascicles with 

 involute-pointed blades 1 to 2 cm. long, the numerous turgid little spikelets clustered 

 at their bases; winter rosette appearing rather late, the lanceolate blades silky-villous 

 like those of the primary culm. 



The vernal form resembles that of P. lanuginosum but is smaller, more slender and 

 more silky-villous, with smaller, more 

 turgid spikelets; the prostrate autumnal 

 form with upturned branch tips is 

 characteristic. 



DISTRIBUTION. 



Sandy pine and oak woods of the 

 Coastal Plain from Virginia to Florida, 



g,^ and west to Louisiana. 



Virginia: Cape Henry, Chase 2341; 





Fig. 231. — Distribution of P. auburne. 



Virginia Beach, Mackenzie 



1733, Williams 3097, 3105; 



Dismal Swamp, Chase 3680. 

 North Carolina: Wilmington, Chase 3132, 4579, Hitchcock 1482; Cumberland 



County, Stevens 6425. 

 South Carolina: Orangeburg, Hitchcock 10. 

 Georgia: Bainbridge, Curtiss 6811; Thomson, Bartlett 1172. 

 Florida: De Funiak Springs, Combs 440. 



Alabama: Gateswood, Tracy 8430 in part; Auburn, Earle & Baker 1527. 

 Louisiana: Shreveport, Cocks 3506. 



O 129. Panicum thurowii Scribn. & Smith. 



Panicum thurowii Scribn. & Smith, U. S. Dept. Agr. Div. Agrost. Circ. 16 : 5. 1899. 

 "Named for Mr. F. W. Thurow, by whom it was collected in Waller County, Texas, 



June 5, 1898, No. 9. " The type, in the National 

 Herbarium, consists of one simple culm and one 

 beginning to branch, about 40 cm. high, with 

 short-exserted, nearly mature panicles. 



DESCRIPTION. 



Vernal form bluish green, but drying olive; 

 culms tufted, 35 to 70 cm. high, erect or ascend- 

 ing, villous, the nodes bearded with spread- 

 ing hairs, usually a glabrous ring below; sheaths 

 long, the lower often overlapping, the upper shorter than the internodes, sparsely 

 or rather densely villous; ligules 4 mm. long; blades rather stiff, ascending 

 or spreading, 7 to 12 cm. long, or the uppermost only 2 to 3 cm. long, 6 to 10 mm. 



Fig. 232.— p. thurowii. 

 type specimen. 



From 



