HITCHCOCK 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. 
QueBeEc: Chandiere River, Macoun 7444 (Herb, Geol. Survey Can.). 
Marne: Holden, Knight in 1893; Mattawamkeag, Fernald 2802; Henderson, 
Parlin 1776. 
New HampesuireE: Alstead, Fernald 361. 
Vermont: Lake Memphremagog, Tuckerman in 1859 (Gray Herb.). 
Connecticut: Hadlyme Ferry, Graves 167. 
RuopeE Isuanp: Lincoln, Fernald in 1906 (Gray Herb.). 
New York: Kinderhook Lake, Peck; Verona, Haberer in 1900. 
New Jersey: Lakehurst, Macken- 
zte 2366. 
PENNSYLVANIA: LancasterCounty, 
Heller 4789. 
Ounto: 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. 
Detaware: Collins Beach, Com- Fi. 41.—Distribution of P. philadelphicum. 
mons in 1879. 
Maryann: 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. 
VirainiA: Four-Mile Run, Hitchcock 166; Alexandria, House 413; Portsmouth, 
Chase 3687; Craigs, Steele 16. 
WEsT Vircinta: Aurora, Steele in 1898; Baileysville, Morris 1283. 
Norra Caro.uina: Chapel Hill, Ashe. 
Sourn Carona: Orangeburg, Hitchcock 7. 
Grorcia: Thomson, Bartlett 1024; Stone Mountain, Harper 184, Hitchcock 439. 
