412 



POLYGONACEAE 



cilia rather elongate; spikes cylindric, 2-3 cm. long, densely 

 many-flowered, erect; flowers about 1.5 mm. long, green with 

 a red tinge; achenes broadly obovoid, black-brown, lustrous, 



lenticular, about 1.2 mm. long. Aug.-Oct. Wet places; 



Honshu (Kazusa Prov.), Kyushu; rather rare. Ryukyus. 



38. Polygonum foliosum H. Lindb. var. paludicola 

 (Makino) Kitam. Persicaria joliosa var. paludicola (Makino) 



Hara; Persicaria paludicola (Makino) Nakai ^Yanagi- 



NUKABO. Usually a more or less reddish annual, 30-60 cm. 

 high; stems slender, elongate, branched above, decumbent at 

 base; leaves broadly linear or narrowly lanceolate, 4-8 cm. 

 long, 3-7 mm. wide, gradually acuminate to acute, nearly 

 sessile or very short-petiolate, sparsely short-appressed pilose 

 on upper side, on the margins and on nerves beneath, often 

 with sessile discoid glands beneath; sheaths 5-10 mm. long, 

 short-pilose, the cilia radier short; spikes rather many, linear, 

 terminal and lateral, loosely flowered, 3-5 cm. long, nodding; 

 flowers green with a red tinge, 1.5-1.8 mm. long; achenes 

 lenticular, elliptic, about 1.5 mm. long, lustrous, black-brown. 



Sept.-Oct. Wet places in abandoned paddy fields, on 



riverbanks and along ditches; Hokkaido, Honshu, Kyushu. 



Korea. The typical phase occurs in Eurasia. 



Var. nikaii (Makino) Kitam. P. ni\aii Makino; P. paludi- 

 cola var. ni\aii Makino; Persicaria foliosa var. ni\aii (Ma- 

 kino) Hara; P. ni\aii (Makino) Nakai Saikoku-nukabo. 



Spikes very loosely flowered; flowers compressed, 2-2.5 mm. 



long. Sept.-Oct. Wet places; Honshu (Kan to Distr. and 



westw.), Shikoku, Kyushu. China. 



39. Polygonum trigonocarpum (Makino) Kudo & Ma- 

 sam. P. minus forma trigonocarpum Makino; Persicaria tri- 



gonocarpa (Makino) Nakai Hosoba-inu-tade. Slender 



annual; stems loosely branched, 30-50 cm. long, reddish 

 brown, glabrous; leaves narrowly lanceolate to linear, 3-7 cm. 

 long, 4-8 mm. wide, gradually narrowed and acute at apex 

 and at base, short appressed-pilose, especially on nerves and on 

 margin, with sessile discoid glands beneath, the petioles very 

 short; sheaths 5-12 mm. long, appressed-pilose and rather 

 long-ciliate; spikes narrowly cylindric, 2-3 cm. long, densely 

 rather many-flowered; flowers 2-2.2 mm. long, reddish, the 

 perianth often with a few sessile glands; achenes trigonous, 



ovoid, lustrous, about 1.8 mm. long. Sept.-Oct. Wet 



places; Hokkaido, Honshu. 



40. Polygonum erectominus Makino. Persicaria erecto- 



minor (Makino) Nakai Hime-tade. Annual; stems 



loosely branched, erect from decumbent or ascending, genicu- 

 late base, loosely rather few-leaved; leaves broadly linear to 

 narrowly lanceolate, 3-8 cm. long, 5-10 mm. wide, subacute 

 or acuminate, obtuse at the tip, vivid to pale green, sometimes 

 purplish beneath, glabrous on upper side, the margin pilose, 

 loosely short-pilose on the nerves beneath, short-petiolate; 

 sheaths 5-12 mm. long, appressed-pilose and short-ciliate, pale 

 green, thinly membranous; spikes erect, short-cylindric, 1.5-2 

 cm. long, many-flowered, interrupted below; flowers glaucous, 

 red, about 2 mm. long; achenes broadly ovoid-ellipsoidal, black, 



lustrous, trigonous, 1.5-2 mm. long. ^May-Oct. Wet places 



along rivers and margins of ponds in lowlands; Honshu, Shi- 

 koku, Kyushu; rather rare. Korea and China. 



41. Polygonum taquetii Lev. Persicaria taquetii (Lev.) 

 Koidz.; Polygonum minutulum Makino; Persicaria minutula 

 (Makino) Nakai; Polygonum taquetii var. minutulum (Ma- 

 kino) Ohwi NuKABO-TADE. Slender ascending to de- 

 cumbent annual 20-40 cm. high; stems branched especially 



below, sometimes scattered appressed-pilose, pale green or 

 pale brown-yellow; leaves thin, lanceolate to broadly linear, 

 2-5 cm. long, 3-7 mm. wide, obtuse to subacute, narrowed to 

 a subsessile base, usually pale green, nearly glabrous to scat- 

 tered appressed-pilose on both sides; sheaths 3-8 mm. long, 

 pale green, appressed pilose and rather short-ciliate; spikes 

 linear or filiform, often branching below, nodding or pendu- 

 lous, terminal and axillary, very loosely or remotely flowered, 

 2-4 cm. long, on capillary peduncles; flowers pale green and 

 rose tinged, 1.5-2 mm. long; achenes ovate, trigonous or lentic- 

 ular, deep brown, 1.5-1.7 mm. long. Sept.-Oct. Wet 



sandy places along rivers in lowlands; Honshu, Shikoku, Kyu- 

 shu. Korea. 



42. Polygonum ajanense (Regel & Tiling) Grig. P. 

 polymorphum var. ajanense Regel & Tiling; Pleuropteropyrum 

 ajanense (Regel & Tiling) Nakai Hime-hva-tade. Gla- 

 brous or pubescent perennial; stems flexuous, erect, sometimes 

 branched, 10-30 cm. long, with ascending branches; leaves 

 lanceolate or broadly so, 3-6 cm. long, 4-10 mm. wide, obtuse 

 or acute, gradually narrowed below to the sessile base; sheaths 

 scarious; inflorescence rather densely flowered, forming a ter- 

 minal nodding panicle; flowers pale green, 3-4 nam. long; 

 achenes included in the perianth, acutely trigonous, brown, 



lustrous, ovoid, about 3.5 mm. long. July-Aug. Alpine 



gravelly and sandy slopes; Hokkaido; rare. s. Kuriles, 



Sakhalin, n. Korea, and e. Siberia. 



43. Polygonum nakaii (Hara) Ohwi. Pleuropteropy- 

 rum na\aii Hara; P. japonicum Nakai, excl. syn. Oyama- 



soba. Rhizomatous loosely tufted perennial; stems erect, 

 spreading, flexuous, 20-40 cm. long, glabrous, rather stout, 

 profusely branched; leaves ovate to broadly so, 4-12 cm. long, 

 2-5 cm. wide, acute to acuminate, rounded to broadly cuneate 

 at base, slightly pubescent, soon glabrate, very shortly petiolate 

 or subsessile; sheaths membranous, long scattered-pubescent or 

 glabrate; spikes erect, terminal, densely many-flowered, panic- 

 ulate, much-branched below; flowers pale green, 3-4 mm. long; 

 achenes slightly longer to as long as the perianth, acutely 

 trigonous, dark yellow-brown, broadly ovoid, 3-3.5 mm. long, 

 lustrous. July-Sept. Alpine gravelly to sandy slopes; Hok- 

 kaido (Hidaka Prov.), Honshu (centr. distr. and northw.). 



44. Polygonum weyrichii F. Schmidt. Pleuropteropy- 

 rum weyrichii (F. Schmidt) Gross Urajiro-tade. Rhi- 

 zomes rather thick; stems slighdy flexuous, erect, stout, 30- 

 100 cm. long, soft-pubescent, branched above; leaves broadly 

 to narrowly ovate, 8-17 cm. long, acuminate, rounded to 

 cuneately rounded at base, appressed-pubescent above, densely 

 white-tomentose beneath, the petioles distinct, usually 1-4 cm. 

 long in the lower ones; sheaths pubescent, rather long; in- 

 florescence paniculate, large, soft-pubescent, much-branched; 

 flowers 2-2.5 mm. long, pale yellow-green; achenes somewhat 

 membranous, broadly ellipsoidal, lustrous, brown, about 8 mm. 

 long, 3 or 4 times as long as the perianth. July-Aug. Hok- 

 kaido (gravelly places near seashores and on alpine slopes), 



Honshu (alpine slopes of n. and centr. distr.). s. Kuriles 



and Sakhalin. 



Var. alpinum Maxim. P. paniculatum sensu Fr. & Sav., 

 non Bl.; P. savatieri Nakai; Pleuropteropyrum savatieri (Na- 

 kai) Koidz.; P. alpinum (Maxim.) Koidz. On-tade. Less 



densely pubescent, green beneath. Alpine gravelly or sandy 



slopes; Hokkaido, Honshu (n. and centr. distr.). s. Kuriles 



and Sakhalin. 



45. Polygonum convolvulus L. Bilderdy\ia convol- 



