400 OCTANDRIA. TRIGYNIA. polygonum, 



ORDER II. 

 TRIGYNIA, 



275. POLYGONUM. L. 



Perianth 5-parted, petaloid, inferior. Nut l-seeded, 

 mostly angular. Gen. pi. 677. Nu 1 1. Gen, I. p^ 

 254. Juss. p. 82. La7n. III. t. 315. Nat. Ord» 

 PoLYGONEiE Juss. StamcHS 5 — 8; styles 2' — 3; 

 leaves ochrtate at the base, Persicaria, Knot-weed, &c, 



* Flowers axillary, 



1. P. aviculare L. : stamens 8 ; styles 3 ; leaves lanceo- 

 late, scabrous o:i the margin; nerves of the stipules distant^ 

 stem procumbent, herbaceous, fV il I d. »S]pec. II. p. '149. 

 Smith Fl. Brit. i. p. 429. Eng. Bot. t. 1252. M i c h. Fh 

 J. p. 237. Pursh FL I. p. 2G9. B i ^. Bost. p. 93. 

 Elliott Sk. I. p. 453, Wa 1 1. Car. p. 132. 



Root fibrous, subligneous, tenacious, annual. Stem much branch- 

 ed, spreading flat on the gi ound, stiiate. Leaves more or less 

 lanceolate, or obovate, attenuate at tlie base. Stipules sheath- 

 ing, scarious, marked with several remote nerves. Flowers 

 2 — 3 in tjie axil of each leaf, nearly sessile, very small. Feri- 

 anth white, tinged with red and green ; segments connivent. 

 Stamens shorter than the perianth. Styles very short. Seed 

 triquetrous, dark brown, minutely striate. 



Hab. In pastures and cultivated grounds, on road sides, &c. ; 

 very common. May — October. Knot-grass. 



i3. latifolium M i c h. : leaves broadly-oval, obtuse ; stem 

 mostly erect. Mich. FL I. p. 237. Pursh FL I. p« 

 269. P. erectum L, W illd. Spec. II. p. 450. 



Stem 3 — 6 inches high, sometimes procumbent. Leaves much 



broader than in the preceding variety. 

 Hab. With the preceding, but more commonly in damp or 



shady places. 



2. P. glaucum JV m N. : flowers octandrous : styles 3 ; 

 leaves lanceolate, thick and glaucous, revolute on the mar- 

 <^in ; stipules lacerate : pedicels exserted ; stem diffuse, pros* 



