HKCOHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



59 



DESCRIPTION. 



Plants light yellowish green, in small tufts, freely branching, erect or rarely decum- 

 bent at base, 15 to 50 cm. high, depauperate, northern specimens sometimes forming 

 small mats; culms slender, papillose-hispid to nearly glabrous, more or less zigzig at 

 base, the lower internodes much shortened; sheaths mostly longer than the internodes, 

 papillose-hispid; blades erect or ascending, 4 to 15 cm. long, 2 to 6 mm. wide, rather 

 sparsely hirsute, rarely nearly glabrous; panicles exserted, diffuse, ovoid, 10 to 20 cm. 

 long, forming one-third the entire height of the plant or more, few-flowered, the 

 capillary, scabrous branchlets solitary, bearing rather short-pediceled spikelets, 

 usually in twos, at the ends; spikelets 1.7 to 2 mm. long, 0.7 mm. wide, elliptic; 

 first glume about two-fifths the length of the spikelet, 5-nerved, acute; second glume 

 and sterile lemma equal, only slightly exceeding the fruit, the palea of the sterile 

 floret wanting; fruit 1.5 mm. long, 0.6 mm. wide, elliptic. 



This species differs from P. capillare in its narrow, erect blades, more slender culms, 

 and smaller, fewer-flowered panicles, with more divergent branches and spikelets 

 mostly in twos. The spikelets are usually slightly smaller, but the spikelets of the type 

 of P. philadelphicum and of several other specimens are 2 mm. long. 



Two specimens from Stone Mountain, Georgia, Harper 184 and Hitchcock 439, have 

 spikelets 2.2 mm. long, and are erect, narrow-leaved plants with somewhat the aspect 

 of P. flexile. 



DISTRIBUTION. 



Dry open or sandy ground, Maine to Wisconsin and Oklahoma, south to Georgia and 

 Mississippi. 



Quebec: Chandiere River, Macoun 7444 (Herb. Geol. Survey Can.). 



Maine: Holden, Knight in 1893; Mattawamkeag, Fernald 2802; Henderson, 

 Parlin 1776. 



New Hampshire: Alstead, Fernald 361. 



Vermont: Lake Memphremagog, Tucherman in 1859 (Gray Herb.). 



Connecticut: Hadlyme Ferry, Graves 167. 



Rhode Island: Lincoln, Fernald in 1906 (Gray Herb.). 



New York: Kinderhook Lake, Peck; Verona, Haberer in 1900. 



New Jersey: Lakehurst, Macken- 

 zie 2366. 



Pennsylvania: Lancaster County, 

 Heller 4789. 



Ohio: Ottawa, Kellerman in 1900 

 (Univ. Ohio Herb.). 



Wisconsin: Sauk City, Luders in 

 1885 ; Granite Heights, Cheney 

 2911. 



Missouri: Monteer, Bush 5119, 

 5120; Readings Mill, Bush 5203. 



Delaware: Collins Beach, Com- 

 mons in 1879. 



Maryland: Glen Echo, Kearney in 1897; Chevy Chase, Chase 2599. 



District of Columbia: Chase 5441, Kearney in 1897, Steele in 1899, Vasey in 1882, 

 Williams 10 in part, 12. 



Virginia: Four-Mile Run, Hitchcock 166; Alexandria, House 413; Portsmouth, 

 Chase 3687; Craigs, Steele 16. 



West Virginia: Aurora, Steele in 1898; Baileysville, Morris 1283. 



North Carolina: Chapel Hill, Ashe. 



South Carolina: Orangeburg, Hitchcock 7. 



Georgia: Thomson, Bartlett 1024; Stone Mountain, Harper 184, Hitchcock 439. 



Fig. 41.— Distribution of P. philadelphicum. 



