164 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 



[Plate 69.] 



70. Polygonum arifolium Linnaeus. 



Polygonum arifolium Linnaeus, Sp. PL 364 (1753); Gmelin, Syst. Nat. 2: 638; 

 Walter, Fl. Car. 132; Willdenow, Sp. PL 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; Eaton, Man. 372; Elliott, Bot. S. C. & Ga. 1 : 459; Barton, Comp. FL Phil. 1 : 189; 

 Sprengel, Syst. 2 : 258; Torrey, Fl. 1 : 407, Comp. 137, Fl. N. Y. 2 : 148 ; Beck, Bot. 303 ; 

 Darlington, Florula Cest. 48, Fl. Cest. 251; Meisner, Monog. 65 and in DC. Prodr. 14: 

 134; Eaton & Wright, N. A. Bot. Ed. 8, 368; A. Gray, Man. 389; Wood, CI. Bk. Ed. 

 475, Am. Bot. and Fl. 284; Chapman, Fl. S. States, 390; Darby, Bot. S. States, 490. 



Perennial or annual, glabrous below, bright green. Stem ascending and reclining, 

 2-9 dm. long, nearly simple or much branched, channeled and armed on the four angles 

 with stout recurved prickles, the peduncles and pedicels glandular or pubescent ; leaves 

 broadly hastate, 2-18 cm. long, 1-16 cm. broad, cordate or subcordate, pubescent or 

 glabrous on the lower surface, more or less constricted below or about the middle, the 

 thin lobes acuminate ; petioles 1-2 cm. long, these as well as the midrib and principal 

 nerves of the leaf armed with recurved prickles; ocreae funnelform, oblique, .5-1 cm. 

 long, fringed at the summit with short bristles and at the base with short bristle-like 

 prickles ; inflorescence terminal and axillary, consisting of suppressed panicled racemes or 

 subcapitate clusters ; racemes 1-2 cm. long, somewhat leafy, interrupted ; bracts funnel- 

 form, oblique, 2 mm. long; pedicels 2 mm. long; calyx greenish or rose-colored, four- 

 parted to below the middle, the segments oblong, obtuse ; stamens eight, included ; style 

 .5-6 mm. long, two-parted to the base, included; achene lenticular, 4 mm. long, obovoid 

 or oblong-ovoid, dark brown or variegated, very smooth and shining. 



New Brunswick to Minnesota south to South Carolina. 



