130 POLYGONACEAE. 



prostrate, much branched, forming dense mats, the branches leafy to the top; 

 leaves oblong or lanceolate, acute, 1-3 cm. long, nearly sessile; sheaths scarious, 

 cut into lobes; flowers 1 or few in the upper axils, pink, on vcr>- short pedicels 

 which are included in the sheaths; alcenes 3-anglcd, dull, minutely granular. 

 Everywhere a weed; much relished by stock. 



Polygonum fowleri Robinson. Perennial, pale green; stems prostrate, 

 branched, 10-50 cm. long, striate; leaves elliptic to oblong, short-petioled, 

 1-3 cm. long, about as long as the internodes; ocreae lacerate and scarious; 

 flowers axillary; sepals oblong, green with the margins white or pink; akenes 

 angular-ovoid, much longer than the calyx. 



On sandy sea-beaches, Alaska to Washington; also on the Alantic coast. 



Polygonum kelloggii Greene. Annual, branched from the base or simple, 

 glabrous, 2-5 cm. high, very leafy; leaves linear or lance-linear, sessile, acute, 

 5-10 mm. long; sheaths thin, lacerate; flowers in small clusters in the axils; 

 calyx 2 mm. long, green with white margins; akenes 3-angled, brown, dull, 

 striate. 



In open places in the mountains, rare in our limits. 



Polygonum erectum L. Annual, yellowish green; stems erect or ascending, 

 20-60 cm. high, simple or branched; leaves elliptical or somewhat obovate, 

 obtuse or acutish, 1-3 cm. long; flowers axillary, solitary or in twos; sepals 

 yellowish-green, 3 mm. long; akene triangular-ovoid, dull, enclosed by the 

 calyx. 



Native of Europe, sparingly introduced in waste places. 



Polygonum minimum Wats. Annual, slightly scabrous, 5-30 cm. high, 

 usually branched from the base; stems wiry, red; leaves oblong-lanceolate, 

 acute or apiculate, 5-12 mm. long; flowers axillary, crowded above, usually 

 rose-colored, erect on short pedicels; stamens 5-8; akenes smooth, shiny, longer 

 than the sepals. 



In moist places at high altitudes, rare in our limits. 



Polygonum douglasii Greene. Annual; stems slender, 15-40 cm. tall, erect, 

 glabrous or nearly so; branches few, erect, angled; leaves lanceolate, acute at 

 each end, sessile at the jointed base; sheaths cylindric, scarious, becoming cut 

 into lobes; flowering branches slender; flowers 1-3, from the axils of the scat- 

 tered bracts, soon becoming deflexed; calyx purple or whitish, with prominent 

 green midribs; styles very short; akene 3-angled, black, shiny. 



In gravelly soil, not common. 



Polygonum spergulariaeforme Meisn. Annual, scurfy pubescent especially 

 at the nodes; stems slender, wiry, loosely branched, erect, 15-30 cm. high; 

 leaves sessile, linear-lanceolate or oblanceolate, acute, 1—3 cm. long, usually 

 revolute on the margin, much reduced upward; sheaths lacerate; flowers in 

 small clusters in the axils, more crowded toward the top; calyx 4 mm. long, 

 green with broad pinkish or white margin; stamens 8; filaments filiform; 

 akene 3-angled, black, minutely roughened, shiny, included in the calyx. 



In poor or gravelly soil, not common. 



Polygonum nuttallii Small. Annual, glabrous; stems slender, angled, wiry, 

 ascending, loosely branched, 5-15 cm. high; leaves narrowly lanceolate or 

 oblanceolate, acute at each end, sessile, 1—3 cm. long; sheaths at length 

 lacerate; flowers axillarv, crowded near the summit; calyx 2.5 mm. long, pink 

 margined; akene 3-angled, black, smooth, shiny. 



British Columbia to Oregon, in open places, not common. 



Polygonimi lapathifolium L. Stems branched, 15-80 cm. high, erect or 

 ascending; leaves lanceolate, acuminate, scabrous on the midrib and margins, 

 10-20 cm. long; peduncles minutely glandular; spikes axillary and terminal. 



