POLYGONACEAE. 131 



slender, 2-10 cm. long, erect or nodding; flowers white or pink; stamens 6; 

 akene ovate, lenticular. 



Sumas Prairie, Lyall; Vancouver Island, Macoun; rare in our limits. 



Polygonum persicaria L. Lady's Thumb. Annual, erect or ascending, 

 glabrous or puberulent; stems 15-90 cm. long; leaves lanceolate, acute or acu- 

 minate at each end, short-petioled, 5-25 cm. long, frequently with a brown- 

 purple spot near the middle, glabrous or sparsely puberulent below and on the 

 midrib margins and above; sheaths tubular, 10—15 mm. long, coarsely fringed; 

 spikes slender, 2-4 cm. long, slender peduncled, erect; calyx pink, 5-lobed; 

 akene lenticular, black and shining. 



Naturalized from Europe, very common. 



Polygonum punctatum Elliott. Perennial or annual, nearly glabrous; stems 

 erect or decumbent at base, often rooting at the nodes, 30-90 cm. long; leaves 

 lanceolate, acuminate, ciliate, 8-12 cm. long; sheaths bristly ciliate; spikes 

 erect, usually densely flowered; calyx greenish with white or pinkish margins; 

 stamens 8; styles 2 or 3; akenes lenticular or'3-angled, smooth and shiny. 



In wet places, not common in our limits. 



Polygonum hydropiper L. Smartweed. Annual, glabrous; stems erect or 

 ascending, 20-60 cm. high; leaves lanceolate, acute or acuminate, ciliate, 

 3-10 cm. long, very acrid; sheaths bristly-ciliate; spikes interrupted, nodding, 

 3-8 cm. long; calyx green, dotted with dark glands; stamens 4 or 6; akenes 

 minutely striate, dull. 



In wet ground, not common, apparently introduced. 



Polygonum newberryi Small. Perennial, dull green, somewhat puberulent 

 throughout; stems stout, rather fleshy, flexuous, mostly simple, 10-30 cm. 

 high; leaves ovate to ovate-oblong, obtusish, 1-4 cm. long, short-petioled; 

 sheaths short, brown, scarious, entire; spikes axillary from the upper leaves, 

 1-2 cm. long, few-flowered; calyx greenish, 5-parted, 3 mm. long; stamens 8; 

 akenes brown, 3-angled, smooth and shiny. 



In rocky soils in the Cascade Mountains at about 2000 m. altitude. 



Polygonum bistortoides Pursh. Perennial from a thick oblong tuber, 

 glabrous throughout or sparsely puberulent; stem erect, simple, 30-60 cm. 

 tall; radical leaves oblong, acute or acuminate, 5-20 cm. long, 3-5 cm. broad, 

 on slender usually shorter petioles; cauline leaves 3-4, sessile, the uppermost 

 much reduced, lanceolate; spikes oblong, 3-6 cm. long, dense; calyx white, 

 deeply 5-cleft; akene chestnut-brown, 3-angled, smooth, shiny. 



Moist meadows in the mountains at 1500 to 2000 m. elevation. 



Polygonum viviparum L. Peiennial from a thick bulb-like base, glabrous; 

 stems strictly erect, simple, 10-30 cm. high; basal leaves oblong-lanceolate, 

 acutish, truncate to subcordate at base, 5-20 cm. long, long-petioled ; cauline 

 leaves lance-linear, sessile; spike terminal, erect, linear, the lower flowers 

 often replaced by bulblets; calyx pink, 5-parted; stamens 8; styles long, ex- 

 serted; akene triangular-ovoid. 



A high alpine plant, collected in our limits only by Lyall, Cascade Mount- 

 ains, latitude 49° 



Polygonum emersum (Michx.) Britt. Perennial, sparsely scabrous 

 throughout; stems erect or decumbent, 1-2 m. long, rooting at the nodes; leaves 

 oblong-lanceolate, acuminate, cuneate or rounded at the base, 8-16 cm. long, 

 short-petioled; sheaths cylindric, loose, entire; spikes dense, 3-7 cm. long, 

 short-peduncled; calyx rose-red, 5-parted; akenes lenticular, black, shiny, 

 slightly roughened. 



In wet meadows; rare in our limits, common east of the Cascade Mountains; 

 Sumas Prairie, Lyall. 



