160 MEMOIRS FROM THE DEPARTMENT OF BOTAISTT OF COLUMBIA COLLEGE. 



[Plate 67.] 

 68. Polygonum Meisnerianum Beyrichianum (Chamisso & Schlechtendal) Meisner. 

 Polygonum Beyrichianum Chamisso & Schlechtendal, Linnaea, 3 : 42 (1828). 

 Polygonum multangulare Hooker <fe Arnott, Comp. Bot. Mag. 2 : 62 (1836). 

 Polygonum Meisnerianum var. Beyrichianum Meisner in Mart. Fl. Bras. 5 : 19 (1855). 

 Polygonum Ghamissoanum Steudel; Meisner, Mart. Fl. Bras. 5: 20 (1855). 

 Polygonum geniculatum Riddell; Meisner, Mart. Fl. Bras. 5: 20(1855). 



Perennial, slender and somewhat wiry, nearly glabrous except the inflorescence and 

 prickly stem. Stem 5-10 dm. long, reclining, dichotomously branched, somewhat en- 

 larged at the nodes, rather sharply angled, the angles mostly armed with recurved 

 prickles; leaves linear or linear-lanceolate, subsagittate, 3-15 cm. long, .4-1.5 cm. broad, 

 acute or acutish, subsessile, cordate and more or less clasping, almost glabrous on the 

 upper surface, glabrous beneath except the midrib Avhich is sometimes sparsely pubes- 

 cent with prickle-like hairs, glandular-ciliate; ocreae cylindric, 1-2 cm. long, somewhat 

 obliquely opened and spreading at the summit, naked, very thin, fringed around the 

 base with small recurved prickles; inflorescence dichotomous, more or less compound, 

 the ultimate divisions ending in clusters or spicate racemes ; peduncles glandular ; racemes 

 .5-1 cm. long, few-flowered; ocreolae 1 mm. long, ciliate; pedicels .8-. 9 mm. long; calyx 

 rose-colored, campanulate, five-parted to the middle, 2-3 mm. long, the segments ovate- 

 oblong, obtuse; stamens five, included; style .5 mm. long, three-parted, included; achene 

 varying from broadly ovoid to obovoid, triquetrous, dark brown, smooth and shining, the 

 faces convex, the angles obtuse. 



Louisiana to Texas and Mexico southward to Brazil. Also in the West Indies. 



