232 



OCTANDRIA TRIGYNIA. 



220. POLYGONUM. Persicavia, Bistort, 

 Knot-grass, and Buckwheat. 



Linn.jGen. ]95. Juss. S2. H.Br. 423. Tourn.t. 290. Lam. t. 315, 



Gcertn. t.ll9. 

 Persicaria, Tourn. t. 290. Gartn. t. \]9. 

 Bistorta, Toiirn. t. 291. 

 Fagopyrum. Tour n. t. 290. Gcertn. t. l\9. 



Nat. Ord. Holeracea. Linn. 12, s. Polygonea:. Juss. 28. 



Cal. inferior, turbinate, more or less coloured, in 5 deep, 

 ovate, obtuse, permanent segments. Cor. none. Filavi. 

 various in number, from 5 to 6, 7, or most generally 8, 

 awl-shaped, very short. Anth. roundish, incumbent. 

 Germ, superior, roundish, either triangular or com- 

 pressed. Styles generally 3, in those with a compressed 

 germen only 2, thread-shaped, very short, in some species 

 partly combined. Stigmas simple. Peric. none, except 

 the closed calyx. Seed solitary, either triangular or com- 

 pressed, pointed; <???i6rvo enveloped in a farinaceous al- 

 humen. 



Generally herbaceous, with knotty, alternately branching 

 stems. Leaves alternate, simple, revolute in the bud ; 

 either sheathing at the base, or attached to an interior, 

 membranous, ribbed, tubular or sheathing, stiimla. Fl. 

 axillary, or terminal, simply stalked, clustered, or spiked; 

 either red, or particoloured with red, green and white. 

 Seed brown, often polished. 



* Styles usually but 2. 



\. P. amphibium. Amphibious Persicaria. 



Styles two, united half way up. Stamens five. Spike ovate. 



P. amphibium. Linn. Sp. PL 5 1 7. mild. v. 2. 443. R. Br. 423. 



Engl.Bot.v.7. t.43o. Curt. Lond.fasc.4. t.28. Hook. Scot. 121. 



FL Dan. t. 282. 

 P. n. 1565. Hall. Hist. v. 2. 261. 

 Persicaria sal icis folio perennis. Rail Syn. 145. 

 Potamogeton salicis folio. Bank. Pin. 193. 

 P. angustifolium. Ger. Em. 821./. 

 P. altera. Dalech. Hist. 1008./. 

 P. sive Stachyites. Lob. Ic. 307./. 



