HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



219 



DESCRIPTION. 



Vernal form subeject or stiffly spreading, bluish green, often purplish; culms 25 to 

 60 cm. high, slender, papillose-pilose, or the upper portion glabrous; sheaths spread- 

 ing-pubescent, rarely nearly glabrous; ligules dense, 4 to 5 mm. long; blades firm 

 with a thin white cartilaginous margin, ascending or suberect, 6 to 9 cm. long, 5 to 8 

 mm., rarely 10 mm., wide (the upper smaller), often sparsely ciliate at base, the veins 

 usually conspicuous, the upper surface glabrous or with a few long, scattered hairs 

 toward the base, the lower surface appressed-pubescent or nearly glabrous; panicle 



4 to 7 cm. long, nearly as wide, rather densely flowered, 

 the lower branches ascending; spikelets 1.6 to 1.7 mm. 

 long, 0.8 to 1 mm. wide, obovate-obtuse, turgid, pubes- 

 cent; first glume about one-fourth the length of the 

 spikelet; second glume shorter than the sterile lemma, 

 leaving the summit of the fruit exposed at maturity; fruit 

 1.4 mm. long, 0.8 mm. wide, elliptic, obtuse. 



Autumnal form widely spreading or decumbent, with 

 numerous fascicled, somewhat flabellate, branches, often 

 forming prostrate mats; leaves much reduced, the blades 

 usually ciliate at base; winter rosette formed early. 



This species resembles P. Undheimeri and P. huachucae silvicola. From the former 

 it differs in the larger spikelets, pilose sheaths, and more or less white-margined blades, 

 which are often pubescent beneath, from the latter, in the firmer blades, glabrous 

 above, and from both in the prostrate, mat-like autumnal form. Two vernal specimens 

 from Connecticut, Graves 13 and 75 in 1899, are referred here doubtfully because of the 

 looser panicle and rather numerous hairs on the upper surface of the blades. Two 

 specimens with spikelets about 2 mm. long are referred doubtfully to P. tennesseense, 

 one from Jefferson County, Missouri (Eggert 242) and one from Sapulpa, Oklahoma 

 (Bush 711). 



DISTRIBUTION. 



Fig. 225.— P. tennesseense 

 type specimen. 



From 



Open rather moist ground and borders of woods, Maine to Minnesota, and south to 

 Georgia, Mississippi, and Arkansas; also in Colorado and Utah. 



Maine: Dover, G. B. Fernald 507; St. Francis, Fernald 166a; Fort Fairfield, 



Fernald 166; Cape Elizabeth, 



Chase 3457; Chesterville, Chase 



3301; Fayette, Chase 3399; 



Hartford, Parlin 2017. 

 New Hampshire : Nashua, Robin- 

 son 789 (Gray Herb.). 

 Vermont: Westmore, Eggleston 



2181 (Gray Herb.). 

 Massachusetts: Framingham, 



Smith 741, 743. ' 

 Connecticut: Hartford, Driggs 3; 



Preston, Graves 11; Branford, 



Bissell 5611. 



» Rhode Island: Providence, Collins in 1891 (Gray Herb.). 

 New York: Thousand Islands, Ball 816, Robinson & Maxon 86; Ithaca, Coville 



in 1885; Apalachin, Fenno 13, 17; Ausable Chasm, Jones in 1898; Jamaica, 



Bicknell in 1905; Valley Stream, Bicknell, in 1905; Rosedale, Bicknell in 1904; 



Rockville Center, Bicknell in 1902; Edgemere, Bicknell in 1902; Hewlett, 



Bicknell in 1905. 

 Ontario: Algonquin Park, Macoun 72965. 



Fig. 226.— Distribution of P. tennesseense. 



