38 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 



[Plate 6.] 

 6. Polygonum Davisiae Brewer. 



Polygonum Davisiae Brewer; A. Gray, Proc. Am. Acad. 8: 399 (1872); S. Watson, 

 Bot. CaHf. 2: 15; Greene, Fl. Francis. 138. 



Perennial from an enlarged and woody rootstock, glabrous and glaucous or incon- 

 spicuously pubescent. Stems usually several from the enlarged base, erect or ascending, 

 .5-4 dm. long, striate, flexuous, sparingly branched above or sometimes simple, leafy 

 throughout; leaves varying from ovate to oblong, sometimes almost lanceolate, 1-8 cm. 

 long, .5-3.5 ciii. broad, obtuse or acutish, sessile or subsessile, varying from subcordate to 

 acuminate at the base, undulate and ciliate, sometimes unsymmetrical ; ocreae funnel- 

 form, .5-1 cm. long, more or less oblique; inflorescence consisting of terminal and axil- 

 lary clusters; clusters loose, two to four-flowered; ocreolae funnelform, 1 mm. or less 

 long; pedicels slender, 2-3 mm. long; calyx purplish green or yellowish, 2.5 mm. long, 

 five-cleft to the middle, much narrowed toward the base ; stamens eight, included ; style 

 about .5 mm. long, three-parted to the base ; achene triquetrous, about 3 mm. long, 

 oblong-ovoid, protruding beyond the persistent calyx, light brown, smooth and shining. 



On the highest slopes of the mountains from Washington to the Sierras of central 

 California. 



