68 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 



[Plate 21.] 

 21. Polygonum persicarioides Humboldt, Bonpland & Kunth. 



Polygonum persicarioides Humboldt, Bonpland & Kunth, Nov. Gen. 2: 197 (1817); 

 Sprengel, Syst. 2 : 257 ; (^-hamisso & Schlectendal, Linnaea, 3 : 44 ; Meisner, Monog. 69, 

 in Mart. Fl. Bras. 5 : 16, and in DC. Prodr. 14 : 117. 



Perennial, nearly glabrous or strigillose. Stem erect or decumbent and creeping, 

 3-7 dm. long, simple or branched either above or from the base; leaves lanceolate or 

 often linear-lanceolate, 3-20 cm. long, .4-2 cm. broad, acuminate at both ends, glabrous 

 or pubescent with scattered hairs, especially on the midrib, ciliate, punctate, short- 

 petioled or subsessile ; ocreae cylindric or funnelform, 1-2 cm. long, glabrous or sparsely 

 strigillose, inconspicuously fringed with short bristles ; inflorescence paniculate, more or 

 less compound, sometimes nearly simple, the ultimate divisions ending in narrow 

 spicate racemes ; racemes erect, 2-6 cm. long, narrowly oblong' or linear, rather loosely 

 flowered ; ocreolae funnelform, oblique, 3 mm. long, fringed with a few short bristles or 

 naked, often glandular or scurfy about the summit ; pedicels about 3 mm. long, more or 

 less angled ; calyx 2-3 mm. long, rose color tinged with green, five-parted to below the 

 middle, the segments oblong, obtvise; stamens eight or fewer, included; style 1-1.5 mm. 

 long, two or three-parted to near the base ; achenes lenticular, biconvex and more or less 

 gibbous, or triquetrous, 2.5-3 mm. long, narrowly ovoid or sometimes broadly oblong, 

 rather long-pointed, black, somewhat granular but shining. 



Nebraska, Texas, New Mexico and Mexico, also in Bolivia, Chili, Paraguay and 

 the Argentine Republic. 



