404 OCTANDRiA. TRIGYNIA. polygonum, 



Hab. On the borders of ponds and lakes. Near New-York ; 

 rare. Ipswich, &c. Massachusetts. Oakes. Near Albany, 

 N. Y. L. C. Beck. In the Highlands of N. Y. Bar- 

 ratt, &c. 



The P. am/iMbium of this country is considered as a dis- 

 tinct species from the European plant by Wi 1 1 d e n o w, and 

 some other authors ; but I am unable to discover any essential 

 difference between them, except that in the latter the leaves 

 (of the var. a.) are scabrous. 



/3. aquaticum : leaves floating, ovate-lanceolate ; spike 

 cylindrical-oblong. Hook. Fl. Scot, part I. p. 121. P. 

 amphibium a. natans M i c h. Fl. I. p. 240. P. natans E a- 

 1 n Man. Bat. ed. 3. p. 400. 



Stem 3 — 10 feet long, branched, spreading on the surface of the 

 water. Leaves petiolate, about 3 inches long, rather obtuse, 

 not cordate at the base, very smootli above and beneath ; mar- 

 gin pilosely ciliate. Sjiike solitary, terminal, emersed, an inch 

 and a half long. 



Hab. Floating in lakes and ponds. Canaan, Columbia county, 

 New- York. Eaton. Danvers, Massachusetts. Oakes. 

 August. 



This can hardly be considered a distinct species, as it is 

 sometimes found passing into the variety «. The European 

 plant appears to be identical with our's. 



9. P. pennsylvanicum L. : flowers octandrous ; style 

 2-cleft ; spike oblong, crowded ; peduncles hispid j leaves 

 lanceolate, slightly hairy ; stipules smooth and naked. 

 Willd, Spec. l\. p.4iS. Jl/i c^. F/. I. p. 240. Pursh 

 FL 1. p. 271. Elliott Sk. I. p. 437. JValt. Car. p, 

 132. 

 Boot annual. Stem 2 — 4 feet high, geniculate, with tumid 

 joints, branched, smooth. Leaves petiolate, often broad-lan- 

 ceolate, pale green, with scattered appressed hairs, particularly 

 on the margin, punctate beneath, under a lens. Stifiules trun- 

 cate. Sfiikes terminal, subpaniculate ; the peduncles glandu- 

 larly hispid. Perianth rose-colour, large. J\rut broad-ovate, 

 compressed, black, smooth and shining. 

 Hab, On the banks of ditches and the borders of fields. July-- 

 October. 



10. P. lapathifolium L. : flowers hexandrous ; styles 2 ; 



spikes oblong, rather crowded, erect ; peduncles scabrous ; 



leaves ovate-lanceolate, on short petioles, hoary. W ill d. 



Spec. II. p. 442. Sm i I h FL Brit. I, p. 425. Eng. Bat. U 



1382. P. incarnatum Elliott Sk. 1. p. 456. 



Foot annual. Stem ?.— 4 feet high, geniculate, smooth. Leaves 

 large, pale green, often hoary beneath, scabrous on the mar- 

 gin. Sfiikes numerous, somewhat paniculate ; fieduncles glan- 

 dularly scabrous, not hispid. Flowers smaller than in the pre- 



