MEMOIRS FROM THE DEPARTMENT OP BOTANY OF COLUMBIA COLLEGE. 



[Plate 26.] 

 26. Polygonum Opelousanum Riddell. 

 Polygo7ium Ojoelousanum 'Riddell; Small, Bull. Torr. Club, 19: 354 (1892). 



Perennial, slender and rather strict. Stem erect or ascending, 3-9 dm. long, spar- 

 ingly or considerably branched, glabrous, becoming woody below; leaves varying from 

 linear-lanceolate to linear, 3-10 cm. long, .3-. 7 cm. broad, glabrous or with a few stout 

 hairs especially on or about the midrib, ciliate, sessile; ocreae cylindric or funnelform 

 at branching nodes, 1-1.5 cm. long, strigose, fringed with long bristles; inflorescence pan- 

 iculate, the ultimate divisions ending in spicate often more or less geminate racemes; 

 racemes almost hnear, 1.5-4 cm. long, erect, not densely flowered; ocreolae funnelform, 

 2.5 mm. long, slightly oblique, conspicuously fringed with long bristles; pedicels 2.5-3 

 mm. long, angled; calyx 1-1.5 mm. long, white, five-parted to below the middle, the 

 segments oblong, obtuse ; stamens eight or fewer, included ; style three-parted to below 

 the middle, about .6 mm. long; achene triquetrous or rarely tetragonous, about 2 mm. 

 long, varying from broadly ovoid to obovoid, black, smooth and shining. 



Southern Missouri and Indian Territory south to Louisiana, Texas and Mexico. 



