POLYGONE^E. 303 



long and slender. Flowers white, axillary and terminal, in small 

 compact heads which are supported on long peduncles. 



15. P. arifolium Linn. : stem prostrate, square, the angles with re- 

 versed prickles ; leaves, on long petioles, hastate, with the lobes acute ; 

 spikes few-flowered ; flowers hexandrous, distinct ; styles bifid. 



HAB. Wet grounds. Can. to Car. Aug., Sept. 0. Stem 

 flexuous, prostrate or climbing. Flowers pale red, in terminal 

 ' and axillary spikes. 



16. P. convolvulus Linn. : stein long, climbing, angular, somewhat 

 rough ; leaves petioled, oblong, hastate-cordate, with the lobes spread- 

 ing and acute ; flowers in lax spikes, octandrous ; styles 3-cleft ; seg- 

 ments of the perianth bluntly keeled. 



HAB. Cultivated grounds. Can. to Car. July Sept. ^ 

 Stem long, climbing. Floioers whitish or reddish, in terminal 

 interrupted spikes or racemes. 



17. P. cilinode Mich* : stem angular, climbing or prostrate, pubes- 

 cent ; leaves petioled, cordate" ; stipules somewhat acute, ciliate at the 

 base ; panicles somewhat leafy ; flowers octandrous ; styles 3-cleft ; 

 segments of the perianth bluntly keeled. 



HAB. Fields. N. S. July, Aug. 0. A variety of the last. ? 



18. P. scandens Linn, : stem climbing, smooth ; leaves broad-cor- 

 date, with the sinus broad and obtuse ; stipules truncate, naked ; flow- 

 ers large, in axillary racemes, octandrous, trigynous ; segments of the 

 perianth winged. 



HAB. Shady woods. N. Y. to Car. W. to Miss. July, Aug. 

 0. Stem purple. Flowers white or reddish, in axillary racemes. 



19. P.fagopyrum Linn. : stem erect, unarmed ; leaves cordate, sag- 

 ittate ; racemes panicled ; angles of the seed equal. 



HAB. Fields ; remaining as a weed where it has been cultivated. 

 June. {$. Buckwheat. 



2. RUMEX. Linn. 



Perianth 6-lcaved. Stamens 6. Styles 3. Nut trique- 

 trous, covered. -by the 3 interior valviform leaves of the peri- 

 anth. Stigmas many-cleft. Hexandria. Trigynia. 



* Flowers all perfect, containing both stamens and pistils. LAPATHUM. 

 t Inner valves of the perianth entire. 



1. R. aquaticus Linn. : valves ovate, entire, all of them granulifer- 

 ous ; leaves lanceolate, acute, the lower ones on long petioles and cor- 

 date at base. 



HAB. Ponds and ditches. N. S. July, Aug. 2f . Root large 

 and very astringent. Stem 3 4 feet high. Flowers whorled, in 

 a terminal leafy panicle. Introduced. 1 Water Dock. 



2. R. crispus Linn. : valves very large, cordate, entire, veined, granu- 

 liferous ; leaves lanceolate, acute, waved at the margin. 



