86 POLYGONACEAE. 



petioles equalling or shorter than the blades; sheaths short; flowers in clusters 

 or slender axillary leafy racemes; calyx 5-parted, closely investing the fruit; 

 akene 3-angled, dull black, minutely roughened. Introduced in cultivated 

 or waste soil. 



Polygonum polygaloides Meisn. Annual, glabrous; stems slender, much 

 branched from the base, 5-20 cm. tall; leaves linear, sessile, 1-nerved, 1-3 cm. 

 long; sheaths scarious, parted into long lobes; spikes dense, numerous, ter- 

 minal, 5-10 cm. long; bracts oblong, with a broad white margin, crenulate, 

 obtuse or acuminate, exceeding the flower; stamens 8; akene 3-angled, long, 

 acuminate, longitudinally striate. Moist meadows, frequent. 



Polygonum confertiflorum Nutt. Annual, glabrous; stems very slender, 

 3-10 cm. tall, with few branches; leaves linear, 1-3 cm. long; sheaths scarious, 

 cut into lobes; spikes few, rather dense, 4-12 mm. long; bracts green, linear, 

 acuminate, longer than the pink flowers, the margins revolute; stamens 3-5; 

 akenes black, minutely striate. In thin soil, rare. 



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, Blue Mountains. 



Polygonum aviculare L. Knot-weed. Annual, glabrous; stems slender, 

 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 very short pedicels 

 which are included in the sheaths; akenes 3-angled, dull, minutely granular. 

 Everywhere a weed; much relished by stock. 



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 scattered bracts, soon becoming deflexed; calyx purple or whitish, 

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

 2n gravelly soil, not common. 



Ptflygonum douglasii montanum Small. Not so tall; leaves broader and 

 shorter; flowering branches more leafy. Gravelly soil in pine woods in the 

 mountains. 



Polygonum majus (Meisn.) Piper. Annual, much branched from the base, 

 erect or nearly so; stems wiry, terete, inconspicuously striate; leaves linear- 

 lanceolate, 2-6 cm. long, jointed at the base; sheaths scarious, about 1 cm. 

 long, at length cut into slender lobes; spikes elongate, 5-12 cm. long; flowers 

 remote, short-pedicelled, horizontal or spreading; bracts consisting of the 

 scarious sheaths and short subulate blades, about as long as the buds; calyx 

 broadly campanulate, 4-5 mm. long, white, with simple green midveins, reach- 

 ing the apex of the short rounded lobes; styles separate for one half their 

 length; fruit reflexed; akene black, shiny, smooth, 3-angled, acuminate, 3-3.5 

 mm. long. Common in stony soil. 



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 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 near 

 the mountains. 



