162 memoirs from the department of botany of columbia college. 



[Plate 68.] 

 69. Polygonum sagittatum Linnaeus. 



Polygonum sagittatum Linnaeus, Sp. PI. 363 (1753); Gmelin, Syst. Nat. 2: 638; 

 Walter, Fl. Car. 132 ; Willdenow, Sp. PI. 2 : 453 ; Michaux, Fl. Bor. Am. 1 : 241 ; Per- 

 soon, Syn. 1 : 441 ; Muhlenberg, Cat. 41; Pursh, Fl. Am. Sept. 272; Bigelow, Fl. Bost. 

 94; Elliott, Bot. S. C. & Ga. 1 : 458; Barton, Comp. Fl. Phil. 1 : 189; Eaton, Man. 372; 

 Sprengel, Syst. 2: 254; 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: 131; Beck, Bot. 302; 

 Darlington, Flornla Cest. 48, Fl. Cest. 251; Eaton & Wright, N. A. Bot. Ed. 8, 368; A. 

 Gray, Man. 390; Wood, CI. Bk. Ed. 41, 475, Am. Bot. and Fl. 284; Chapman, Fl. S. 

 States, 390 ; Darby, Bot. S. States, 490. 



Polygonum sagittatum var. boreale Meisner, Monog. 65 (1826). 



Polygonum sagittatum var. Americanum Meisner in DC. Prodr. 14 : 132 (1856). 



Polygonum sagittatum var. puhescens 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 cm. long, .5-3 cm. broad, cordate, the lower 

 ones long-petioled, the U23per shorfc-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 cm. long, armed, as Avell 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. 



