118 MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA COLLEGE. 
[Piate 46. ] 
46. Polygonum Douglasii Greene. 
Polygonum tenue Engelmann; A. Gray, Proc. Acad. Phila. 75 (1863), not Michaux; 
S. Watson, Bot. King’s Exp. 315, Bot. Calif. 2: 12; Coulter, Man. Bot. Rocky Mt. Reg. 319. 
Polygonum tenue var. commune Engelmann; A. Gray, Proc. Acad. Phila. 75 (1863). 
Polygonum Douglasii Greene, Bull. Calif. Acad. Sei. 1: 125 (1884), Fl. Francis. 134. 
Annual, slender, glabrous except the more or less scabrous nodes, sometimes glau- 
cescent. Stem erect, 2-4 dm. long, nearly simple or branched from the base or through- 
out, lax or strict, almost terete or somewhat ridged; leaves oblong or narrowly lanceolate, 
1-5 em. long, .2-.8 em. broad, obtuse, acute or cuspidate, subsessile or sessile, acuminate 
at the base, rather thin, flat, or somewhat revolute, with no lateral impressions, joined to 
the ocreae by conspicuous articulations; ocreae funnelform, oblique, 10-14 mm. long, two- 
parted, at length lacerate; inflorescence axillary, the clusters several-flowered or occasion- 
ally only a single flower at a node; pedicels 2-3 mm. long, reflexed and at length de- 
flexed; calyx greenish, 3-4 mm. long, drooping, five-parted to near the base, the segments 
oblong, obtuse, with whitish or rose-colored margins and a dark rib in the middle; 
stamens eight, included; style .8 mm. long, three-parted to near the base, the segments 
somewhat divergent and slightly protruding beyond the calyx at maturity; achene tri- 
quetrous, 3-4 mm. long, oblong or rarely ovoid-oblong, black, smooth and shining. 
Northwest Territory to California, New Mexico and Indian Territory, east to 
Ontario, Vermont and New York. 
Polygonum Douglasii montanum Small. 
Polygonum tenue var. latifolium Engelmann, Proc. Acad. Phila. 75 (1863), not P. 
aviculare var. latifolium Michx. (1803); 5. Watson, Bot. King’s Exp. 315; Coulter, Man. 
Bot. Rocky Mt. Reg. 319. 
Polygonum Douglasii var. latifolium Greene, Bull. Calif. Acad. Sei. 1: 125 (1884), 
Fl. Francis. 134 
Stout, more or less fleshy, glaucescent; stem erect, .5-2.5 dm. long or sometimes pros- 
trate, simple or sparingly branched from near the base; leaves oblong or oblanceolate, 
1-4.5 mm. long, 2-12 mm. broad, apiculate, sessile; inflorescence mostly towards the 
ends of the branches; achene triquetrous, 3 mm. long, oblong, black, smooth and shining. 
Arizona to California and northward in the higher mountains. 
