POLYGONACEAE 453 
BaL with the upper leaves scattered and reduced in. 
5. P. camporum. 
Calyx, ae least the inner sepals, yellow or yellow-green. 
Leaf-blades broad: achene dull. 6. P. erectum 
Leaf-blades narrow: achene shining. (Coe P. ramosissimum. 
II. TEN 
Annual with erect wiry stems and very sade panicles, the 
clusters often reduced to a single flower each. 8. P. tenue. 
1. P. glaucum Nutt. Plant glaucous, sometimes nearly white, the branehes 
mainly prostrate or assurgent, 2-7 dm. long: leaf-blades fleshy, generally longer 
j e m 2/0 
wide: ocre l very conspicuous 
perianth beco mm. long; als 
e 
[P. maritimum (Fl SE. U. 8.) J— 
enm mung Fla. to Ala. and Me—(£u.) 
2. P. aviculare L. Plant bright-green, the 
branches ultimately procumbent or prostrate, 
1-6 dm. long: leaf-blades thin or thinnish, 
: eae very thin: 
3 
KNOTGRASS.)—Fields, roads, and 
places, various provinces, Fla. to La., Calif, and C Can.—(Eurasia.) 
3. neglectum Besser. Plant bright-green or bluish-green, the branches ulti- 
ES prostrate or proeumbent, 1-6 dm. long: leaf-blades thin, narrowly ellip- 
tic, pees o or linear, pU 2-3 mm. wide, acute or acuminate: 
ocreae very thin: perianth ru ing 1.5-2 mm. jou: sepals with pale-pink or 
purplish-red Dodd s: achene 1.5-2 mm. long, dull, granular-striate. — Common, 
about dwellings, and on das e and in waste places, various provinees, Fla. 
to Tex., Calif., and S Can.—(Enurasia.) 
4. P. s iforme Small. Plant bright-green or pale-green, the E odd s 
diffuse dd 2-8 dm. long: leaf- d thiek, mainly 4—10 mm. wide: 
ocreae Nnm : perianth b ey ming 2-3 mm. long; sepals with ic Or car- 
mine borders: nea 2-2. . long, often granular, TA fields, and 
waste places, a E R oN C. to Tex., N. M., B. C., Ont., and N. B. 
P. camporum Meisn. Plant a green, 9-12 dm. tall: leaf-blades ap di 
o Or uim to linear, varying to oblanceolate or lanceolate, 1-3 mm. long: 
peri e becoming about 2 mm. lo ong; sepals veiny in age: achene broadly ovoid, 
2 mm. long or Pac SO, thinnis, acute.—Low grounds, Coastal Plain, La. and 
Tex. Nat. in Ala.— —(Menz.) 
6. P. erectum L. Plant yellowish-green, the lower gd spreading or de- 
eumbent, 1-12 dm. long: leaf-blades much larger than in any of the preceding 
i i elli ova ward: 
1 —6 em. lon 
ocreae rather bd perianth becoming 3.5 mm. long; sepals often veiny in 
e: achene m. long, striate, dull.— Yards, ae places, and moist banks, 
various ven anum Ga. to Ark., Man., Ont., and Me. 
P. ramosissimum Michx. Plant yellow- de 2.5-13 dm. tall usually 
eee branched ane bur blades mainly 2-5 em. long: ocreae conspicuous: 
perianth becoming 2.5 . long; sepals ee veiny at maturity: achene 
