HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 259 



152. Panicum tenue Muhl. 



Panicum tenue Muhl. Descr. Gram. 118. 1817. No locality is given. "P. deustum 

 Brickell et Enslin," an unpublished name, is cited as synonym. The type, in the 

 Muhlenberg Herbarium, consists of three plants with attached label bearing the name 

 ''Panicum deustum'" these are from 10 to 30 cm. high, the panicles immature, the 

 sheaths sparsely appressed-pilose, the blades puberulent on the lower surface and 

 with conspicuous white margins. 



Panicum deustum Brickell & Enslin; Muhl. Descr. Gram. 119. 1817, not Thunb. 

 1794. This herbarium name is given as a synonym of P. tenue, of which it is a typonym. 



Panicum liton Schult. Mant. 2 : 250. 1824. Based on P. tenue Muhl., Muhlenberg's 

 description, slightly rearranged, being copied, " Nomina mutanda, ob tenue R-oxb. et 

 deustum Thunb. antiquiora." Panicum tenue Roxb. 1813, « is a nomen nudum, the 

 description not being published until 1820. & 



Panicum unciphyllum Trin. Gram. Pan. 242. 1826. Trinius states in regard to his 

 specimen, "V. spp. Am. Bor. (Trattinick)." The type, in the Trinius Herbarium, 

 is the vernal form, with sparsely appressed- villous culms and sheaths and puberulent 

 blades. As stated under P. columbianum, Trinius's species was misunderstood because 

 the specimen sent from St. Petersburg as a part of the type proved on a subsequent 

 examination of Trinius's herbarium to be not the type but a specimen of P. colum- 

 bianum which was on the same sheet with the type specimen. The label accompany- 

 ing the latter reads, "Panicum unciphyllum m. Pan. heterophyllum Muhl. (teste 

 Nees) an Pluckn. Tav. 92 f. 8, ex herb. Enslini, spmna Am. bor. Trattinick." 



Panicum macrum Kunth, Rev. Gram. 1:40. 1829. Based on P. tenue Muhl., 

 the name presumably changed because of P. tenue Roxb. 



Panicum parvulum Muhl.; Scribn. & Merr. U. S. Dept. Agr. Div. Agrost. Circ. 

 27: 4. 1900, not Trin. 1834. This name, found in Muhlenberg's herbarium, is given 

 as a synonym of P. tenue. 



DESCRIPTION. 



Vernal form olive green; culms in rather small tufts, 20 to 55 cm. high, slender, 

 erect from a more or less geniculate base, glabrous, or the lower internodes sparsely 

 appressed-pubescent, the nodes glabrous, appressed-pubescent, or appressed-pilose; 

 sheaths usually much shorter than the internodes, puberulent between the nerves 

 to sparsely appressed-pilose, or the upper glabrous; ligules 0.3 to 0.5 mm. long, dense; 

 blades distant, ascending or speading, 2 to 5 cm. long, 3 to 4 mm. wide, rather thick 

 and with a cartilaginous, often white, margin, involute-pointed, usually densely 

 puberulent beneath, glabrous on the upper surface or puberulent toward the base; 

 panicles long-exserted, 3 to 5 cm. long, about as wide, pyramidal, open, rather few- 

 flowered, the flexuous branches spreading; spikelets 1.6 to 1.7 mm. long, elliptic, 

 subobtuse, densely puberulent; first glume one-fifth as long as the spikelet or less, 

 obtuse; second glume shorter than the fruit and sterile lemma; fruit 1.4 to 1.5 mm. 

 long, elliptic, subobtuse. 



Autumnal culms erect or leaning, sparingly branching from the middle nodes, the 

 branches in small fascicles, shorter than the primary inter- 

 nodes, the blades not much reduced; winter rosette con- 

 spicuous, the thick, cartilaginous-margined, involute-pointed 

 blades 3 to 5 cm. long, 4 to 7 mm. wide, persistent (but usu- 

 ally dead) during the succeeding year. 

 This species seems to be intermediate between P. albo- 

 FlG ' T'^'edmen ^^ mar 9 inatum and P - ensifolium, differing from the first in 

 being pubescent and in having taller, more slender 

 culms, sparingly branched. From P. ensifolium it may be distinguished by the larger, 



a Cat. Fl. Ind. 1813. & Roxb. Fl. Ind. 1: 313. 1820. 



