162 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 
[PLATE 68.] 
69. Polygonum sagittatum Linnaeus. 
Polygonum sagittatum Linnaeus, Sp. Pl. 363 (1753); Gmelin, Syst. Nat. 2: 638; 
Walter, Fl. Car. 132; Willdenow, Sp. Pl. 2: 453; Michaux, Fl. Bor. Am. 1: 241; Per- 
soon, Syn. oe Muhlenberg, Cat. 41; Pursh, FL Am. Sept. 272; Bigelow, Fl. Bost. 
94: Elliott, Bot. 8. C. & Ga. 1: 458; Barton, Comp. Fl. Phil. 1: 189; Eaton, Man. 372; 
Sprengel, Syst. 2: . 95 4; Torrey, Fl. 1: 407, Comp. 173, and Fl. N. Y. 2: 148; Meisner, 
Monog. 64 and in DC. Prodr. 14: 132; Hooker, Fl. Bor. Am. 2: 181; Beck, Bot. 302; 
Darlington, Florula Cest. 48, Fl. Cest. 251; Eaton & Wright, N. A. Bot. Ed. 8, 368; A. 
Gray, Man. 390; Wood, Cl. Bk. Ed. 41, 475, Am. Bot. and Fl. 284; Chapman, FI. 8. 
States, 390; Darby, Bot. 8. States, 490. 
Polygonum sagittatum var. boreale Meisner, Monog. 65 (1826). 
Polygonum sagittatum var. Americanum Meisner in DC. Prodr, 14: 132 (1856). 
Polygonum sagittatum var. pubescens Keller, Bull. Soc. Bot. Belg. 30: 45 (1891). 
Annual, glabrous, bright green throughout or parts tinged with red. Stem slender 
or stout, decumbent, ascending or reclining, 3-15 dm. long, simple or much branched, 
four-angled and finely channeled, armed on the angles with sharp recurved prickles, by 
which the plant climbs, the length of the internodes variable on the same plant; 
leaves lanceolate or oblong, sagittate, 1-12 em. long, .5-3 em. broad, cordate, the lower 
ones long-petioled, the upper short-petioled or subsessile, obtuse or acute, lighter green on 
the lower than on the upper surface, slightly roughened on the edge by small prickles; 
petioles 1-5 em. long, armed, as well as the midrib, with small recurved prickles; 
ocreae funnelform, very oblique, .5-1 cm. long, acute, smooth, eciliate; inflorescence 
terminal, consisting of capitate sometimes panicled clusters; ocreolae bract-like, lanceo- 
late, 3-5 mm. long; pedicels 1.5 mm. long; calyx white, green or red, 4 mm. long, five- 
parted to below the middle, the segments oblong, obtuse; stamens eight, included; style 
9 mm. long, three-parted to below the middle, included; achene triquetrous, 3-3.5 mm. 
long, ovoid, sharp-pointed, black or brownish, smooth and shining. 
Newfoundland to the Saskatchewan south to Florida and Texas. 
