108 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Fig. 103. — Distribution of P. ariceps. 



especially at the summit; ligules membranaceous, less than 1 mm. long; blades erect, 

 flat or but slightly conduplicate at base, 20 to 50 cm. long, 4 to 12 mm. wide, pilose and 

 usually ciliate on the upper surface toward the base, otherwise glabrous, scabrous or 

 more or less pubescent on the upper and occasionally on the under surface; panicles 

 terminal only, or narrow, long-peduncled panicles produced from the upper sheaths, 

 the terminal ones finally long-exserted but often nearly equaled by the long blades, 

 15 to 40 cm. long, usually half to two- 

 thirds as wide (or occasionally narrow), 

 the long, slender, remote, branches 

 somewhat spreading, bearing short, 



mostly appressed, distant or approxi- { J""'"'r~-^ i {_~"\--0-r^^"~^'Xf^ -W^'^^ 



mate branchlets with rather crowded, ' ' " 



somewhat curved, subsecund spikelets 

 set obliquely on their short, appressed, 

 scabrous pedicels, the first glume to- 

 ward the main axis, the axes and 

 branches scabrous, usually a few hairs 

 in the axils; spikelets 3.4 to 3.8 mm. 

 long, 1 to 1.2 mm. wide (occasional 



specimens with smaller spikelets); first glume one-third to half the length of the spike- 

 let, acute; second glume and sterile lemma subequal, forming a beak beyond the fruit, 

 the tips open at maturity; fruit 2 to 2.2 mm. long, about 1 mm. wide. 



This species is variable in the pubescence on sheaths and blades and somewhat so 

 in the panicle. The short secondary branchlets may be distant, giving the long 

 branches the appearance of interrupted racemes, or approximate, producing densely 

 flowered branches as in Vasey's variety densiflorum. 



A comparatively few specimens occur with spikelets only 3 to 3.2 mm. long. 

 Such are the following, which, being nearly glabrous plants with open panicles, are 

 referred here, though in the smaller spikelets they approach the next species: Ball 228, 

 Chase 4201, 4393, 4554, Cocks 3001, Combs 717, 878, 1398, Kearney 376, Mohr in 1885, 

 Tracy 4620, 8414. 



DISTRIBUTION. 



Moist sandy soil. New Jersey to Florida and west to Kansas and Texas. 



New Jersey: Stockton, Fisher in 1897 . 



Pennsylvania: Philadelphia, Smith; Lancaster, Porter in 1861. 



Illinois: Oquawka, PaMerson; Mount Carmel, WaitemlS87. 



Missouri: Monteer, Bush 5114; St. Louis, Eggert in 1886. 



Kansas: Cherokee County, Eitchcoch PL Kan. 876. 



Delaware: Carpenter Station, Commons 225; Greenbank, Commons 303. 



Maryland: West Chevy Chase, Chase 2585; Cabin John, Steele in 1896. 



District op Columbia: Blanchard in 1891, Chase 2996, House 257, Kearney 16, 

 Vasey in 1874, Ward in 1878. 



Virginia: Fairfax County, Chase 3631; Arlington, Dewey 53; Norfolk, Kearney 

 1748; Virginia Beach, Britton in 1895, Hitchcock 228. 



North Carolina: Madison County, Biltmore Herb. 5839b; West Raleigh, Coit 

 1301, Stanton 1282; Dunns Mountain, Small in 1894; eastern North Caro- 

 lina, McCarthy in 1885; Wilmington, Kearney 274. 



South Carolina: Aiken, Ravenel in 1869; Orangeburg, Hitchcock 448, 449; Isle 

 of Palms, Chase 4554. 



Georgia: Thomson, Bartlett 903; Whitfield County, Harper 369; Stone Moun- 

 tain, Siic/icoc/; 230; Leesburg, Curtiss 6887 ; Augusta, Cuthbert in 1904. 



Florida: Madison, Combs 282; Quincy, Combs 415; Tallahassee, Conibs 381, 

 Kearney 87, Nash 2529; De Funiak Springs, Com6s 470; Chattahoochee, Cur- 



