110 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



spikelets and by the shorter leaves more or less crowded at the base. In occasional 

 specimens the panicle is rather open but less so than in P. anceps; but the following 

 three specimens, having all the other characters of P. rhizomatum, have panicles as open 

 as those of P. anceps, the small spikelets secund as in that species, and appear to be 

 intermediate. Florida: Bay Head, 

 Combs 648; Orange County, Baker 40; 

 Mississippi: Starkville, Kearney 61; 

 Waynesboro, Kearney 108. 



DISTRIBUTION. 



Moist sandy woods and savannas, 

 Virginia to Forida and west to Texas. 



Virginia: Lynn Haven, Hitchcock 

 175; Portsmouth, Noyes 67 in 

 p ar t,. Fig. 105.— Distribution of P. rhizomatum. 



North Carolina: Wilmington, Chase 4560, Hitchcock 310. 



South Carolina: Orangeburg, Hitchcock 450; Isle of Palms, Hitchcock 104; with- 

 out locality, Curtiss in 1875. 



Georgia: Savannah, Kearney 181; Dock Junction, Ricker 962; Camp Cornelia, 

 Richer 933. 



Florida: Jacksonville, Curtiss 5289, 5747, Kearney 138; Duval County, Curtiss 

 3579 in part; Madison, Combs 259; Old Town, Combs 884; Lake City, Combs & 

 Rolfs 120, 192; Waldo, Combs 700; Gainesville, Chase 4201$, 4220, 4271; 

 Citrus, Bystra in 1906; Titusville, Chase 3984; Sanford, Nash 2258; Grasmere, 

 Combs 1051, 1125; Eustis, Nash 1713; Ellzey, Combs 820; Dunnellon, Combs 

 919; Bay Head, Combs 633, 648; Tampa, Combs 1395 ; Avondale, Combs 496; 

 Bartow, Combs 1192, 1217a; Braidentown, Combs 1252, 1264, 1303, Tracy 7093, 

 7105; Myers, Chase 4191, Hitchcock Lee Co. PL 490. 



Alabama: Without locality, Mohr in 1878. 



Mississippi: Centerville, Tracy 4564; Nicholson, Kearney 358; Biloxi, Kearney 

 235, Tracy 3603, 3626, 4619, 4621, and in 1889; Ocean Springs, Forkert 33, Pol- 

 lard 1106; Bay St. Louis, Langlois in 1883; Pass Christian, Langlois in 1880 

 and 1882. 



Louisiana: Natchitoches, Ball 137. 



Texas: Pierce, Tracy 7405; without locality, Nealley. 



Laxa. — Plants mostly perennial, apparently annual in P. laxum and P. pilosum, 

 more or less decumbent at base and rooting at the lower nodes, creeping in 

 P . polygonatum, commonly not decumbent in P. Mans and P.cupreum; 

 culms compressed, glabrous; ligules membranaceous, very short or wanting; 

 spikelets short-pediceled, more or less clustered, not over 3 mm. long, 

 glabrous, the palea of the sterile floret, except in P . polygonatum and P. 

 longum, becoming more or less enlarged and indurated, expanding the spike- 

 let at maturity; fruit mostly elliptic, minutely papillose-roughened, rather 

 thin in texture. 

 Spikelets pointed, not expanded at maturity by an enlarged sterile palea. 

 Nodes densely pubescent; spikelets not over 1.5 mm. 



long 58. P. polygonatum. 



Nodes glabrous; spikelets 2.5 mm. long 57. P. longum. 



Spikelets blunt, expanded at maturity by the enlarged sterile 

 palea, 

 Panicle branches subracemose, the spikelets secund; 

 blades at least 5 mm. wide; the enlarged sterile 

 palea not conspicuous. 



