120 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 



[Plate 47.] 

 47. Polygonum Sawatchense Small. 

 Polygonium Sawatchense Small, Bull. Torr. Club, 20: 213 (1893). 



Annual, usually slender, glabrous, more or less scurfy or papillose throughout, of a 

 dull green color. Stem erect, .5-2 dm. long, nearly simple or branched from or near the 

 base, minutely ridged, obscurely four-angled and four-winged below the ocreae ; leaves 

 oblanceolate, narrowly obovate, or almost linear near the ends of the branches, .5-2 cm. 

 long, 1-6 mm. broad, acute, sessile, acuminate at the base, fiat or re volute, often much 

 the same length even to the ends of the stems, joined to the ocreae by conspicuous articu- 

 lations, midrib prominent on the lower surface and often wing-like ; ocreae funnelform, 

 oblique, 4-6 mm. long, two-parted, at length lacerate to the middle ; inflorescence axil- 

 lary, consisting of clusters with from two to four flowers and extending to the base of the 

 plant ; pedicels 2 mm. long ; calyx green, 2-3 mm. long, five-parted to near the base or 

 to below the midde, the segments oblong, obtuse, only slightly lighter-colored on the 

 margins; stamens 6-8; style almost wanting, stigma three-cleft, included; achene tri- 

 quetrous, 2.5-2.8 mm. long, oblong, rather obtuse at both ends or sometimes acute at the 

 apex, black, very smooth and shining. 



Dakota to Washington south to Colorado. 



