122 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 



[Plate 48.] 

 48. Polygonum tenue Michaux. 



Polygonum tcnue Michaux, Fl. Bor. Am. 1: 238 (1803); Persoon, Syn. 1: 439; 

 Pursh, Fl. Am. Sept. 270 ; Eaton, Man. 370 ; Elliott, Fl. S. C. and Ga. 1 : 454 ; Sprengel, 

 Syst. 2 : 256; Torrey, Fl. 1 : 401, Comp. 171 ; Meisuer, Monog. 91 and in DC. Prodr. 14 : 

 100; Darlington, Florula Cest. 48, Fl. Cest. 248; Hooker, Fl. Bor. Am. 2: 132; Beck, 

 Bot. 301 ; Bigelow, Fl. Bost. 155; Eaton & Wright, N. A. Bot. Ed. 8, 367 ; A. Gray, Man. 

 389; Wood, CI. Bk. Ed. 41, 474, Am. Bot. and Fl. 283; Chapman, Fl. S. States, 390; 

 Darby, Bot. S. States, 488; Greene, Bull. Cal. Acad. Sci. 1: 125; Coulter, Man. Bot. 

 Rocky ]\It. Reg. 319. 



Polygonum Hnifolium Muhlenberg, Cat. 40 (1813); Barton, Comp. Fl. Phil. 1 : 186; 

 Wood, CI. Bk. Ed. 41, 474. 



Polygonum Jiliformis Barton, Comp. Fl. Phil. 1 : 186 (1818), not Thunb. 



Polygonum teiiue var. commune Engelmann; A. Gray, Proc. Acad. Phila. 75 (1863). 



Annual, slender, glabrous throughout or somewhat scabrous and scurfy about the 

 nodes. Stem erect, 1-3 dm. long, simple or much branched, more or less four-angled or 

 four-winged below the ocreae; leaves linear or linear-lanceolate, .5-3 cm. long, .1-.3 cm. 

 broad, acuminate or cuspidate, sessile, with two lateral impressions appearing as ribs 

 parallel to the midrib, articulated to the ocreae, minutely scabrous on the margin, more 

 or less scurfy on the lower surface, sometimes revolute; ocreae funnelform, oblique, 3-15 

 mm. long, two-parted, at length lacerate; inflorescence axillary, consisting of clusters 

 bearing several flowers or sometimes only one flower at a node; pedicels stout, 1-1.5 mm. 

 long; calyx green, 3 mm. long, erect, five-parted to near the base, the segments ovate, 

 acutish, A\'ith whitish margins; stamens eight, included; style .3-.4 mm. long, three- 

 parted to near the base, the segments diverging, included or protruding slightly beyond 

 the calyx; achene triquetrous, 3 mm. long, ovoid, pointed, black, granular about the 

 angles, the centres of the faces smooth and shining. 



Canada to Minnesota south to Georgia and New Mexico. 



