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. FLiortpa: 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. 
Vireinta: Lynn Haven, Hitchcock 
175; Portsmouth, Noyes 67 in 
part. Fig. 105.—Distribution of P. rhizomatum. 
Norte Carortna: Wilmington, Chase 4560, Hitchcock 310. 
SoutH Carona: Orangeburg, Hitchcock 450; Isle of Palms, Hitchcock 104; with- 
out locality, Curtiss in 1875. 
Groraia: Savannah, Kearney 181; Dock Junction, Ricker 962; Camp Cornelia, 
Ricker 933. Peis 
Froriwwa: 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 42014, 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. P1. 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. 
Lourstana: 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. hians 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. 
ios cNeos a MR MEU EN AOR cope tna ae ney Mees NEES SS 8 eS 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. 
