66 memoirs from the depaetment of botany of columbia college. 



[Plate 20.] 

 20. Polygonum Persicaria Linnaeus. 



Polygoaam Pemmrla Linnaeus, Sp. PL 361 (1753); Gmelin, Syst. Nat. 2: 638; 

 Walter, Fl. Car. 131 ; Michaux, Fl. Bor. Am. 1 : 239 ; Persoon, Syn. 1 : 440 ; Bigelow, 

 Fl. Best. 94; Pursh, Fl. Am. Sept. 271; Muhlenberg, Cat. 40; Barton, Comp. Fl. Phil. 

 187; Eaton, Man. 371; Torrey, Fl. 1: 405, Comp. 172; Sprengel, Syst. 257; Meisner, 

 Monog. 68, in Mart. Fl. Bras. 5: 16, in DC. Prodr. 14: 117; Beck, Bot. 302; Darling- 

 ton, Florula Cest. 48, Fl. Cest. 249 ; Hooker, Fl. Bor. Am. 2 : 132 ; Eaton & Wright, N. 

 A. Bot. Ed. 8, 368; A. Gray, Man. 387; Wood, CI. Bk. Ed. 41, 474, Am. Bot. & Fl. 

 283; Gay, Fl. Chil. 5: 266; Chapman, Fl. S. States, 389; S. Watson, Bot. Calif. 2: 14; 

 Greene, Fl. Francis. 136, Man. Bay Reg. Bot. 42. 



Polygonum Persicaria var. vernicosnm Chamisso & Schlechtendal, Linnaea, 3 : 43 

 (1828), Gay, Fl. Chil. 5 : 266. 



Polygonuni Persicaria var. vulgare Meisner, Monog. 68 (1826). 



Annual, smooth or puberulent. Stem erect or sometimes spreading, 2-8 dm. long, 

 simple or branched either at the base or above or throughout ; leaves varying from lan- 

 ceolate to linear-lanceolate, 2-18 cm. long, 3-3.5 cm. broad, acuminate at both ends, en- 

 tire or sometimes eroded, often somewhat ciliate, conspicuously punctate, nearly smooth 

 except the more or less hispid midrib and nerves, short-petioled or subsessile, generally 

 with a dark triangular or lunar spot in the middle; ocreae cylindric or funnelform, 1-1.5 

 cm. long, nearly smooth or with short hairs on the ridges, usually conspicuously fringed 

 with short bristles; inflorescence paniculate, more or less compound, the ultimate divi- 

 sions narrow spicate racemes; racemes oblong or ovoid, 1-3 cm. long, .5-1 cm. thick, 

 mostly erect, densely flowered; ocreolae funnelform, 1.5-2 mm. long, oblique, smooth or 

 nearly so, fringed witli short bristles; pedicels 1-2 mm. long; calyx about 1.5 mm. long, 

 \'arying from pink to dark purple or sometimes red or greenish, flve-cleft to the middle, 

 the segments obtuse ; stamens generally six, included ; style two or three-parted to below 

 the middle or near the base, 1-2 mm. long ; achenes lenticular, biconvex, often gibbous 

 or triquetrous, 2-2.5 nun. long, broadly ovoid, pointed, black, smooth and shining. 



Throughout temperate and tropical North and South America. Naturalized from 

 Europe. 



