302 DICOTYLEDONOUS PLANTS. 



1. Stem -812 inches long. Flowers large, reddish, in 

 an ovate spike. Var. b. has the stems long and the leaves 

 broad cordate and floating ; but it passes into the former variety. 



9. P. pennsylvanicum Linn. : stem with tumid joints^ smooth ; leaves 

 lanceolate, slightly hairy, petioled ; stiptales smooth and naked ; flow- 

 ers in crowded oblong spikes, octandrous ; style 2-clefl ; peduficles 

 hispid. 



HAB. Margins of ponds and ditches. N. Y. to Car. July Sept. 

 . Stem 24 feet high, 'geniculate. Flowers large, reddish, 

 in crowded spikes. 



10. P. lapathifolium Linn. : stem geniculate, smooth ; leaves ovate- 

 lanceolate, on short petioles, often hoary beneath ; spikes numerous, 

 rather crowded, erect ; peduncles scabrous ; flowers hexandrous ; 

 styles 2. P. incarnatum Ell. 



HAB. Ditches and swamps. N. Y. to Car. Aug., Sept. . 

 Stem 2 3 feet high. Floicers white or pale red, smaller than in 

 the former. 



11. P. persicaria Linn. : stem erect ; leaves on short petioles, lanceo- 

 late, the upper surface marked with dark coloured spots; stipules 

 smooth, ciliate ; spikes dense, terminal, ovate-oblong, erect ; flowers 

 hexandrous ; styles bifid. 



HAB. Wet grounds. July, Aug. . Stem 12 18 inches high, 

 branched, smooth, often red. Flowers reddish, in erect oblong 

 terminal spikes. Ladies' Thumb. 



12' P. orientale Linn. : stem erect ; leaves very large, petioled, 

 ovate, acuminate, minutely pubescent ; stipules hairy, hypocrateri- 

 form ; flowers in crowded terminal spikes, hexandrous, digynous. 



HAB. Old fields and roads sides. July, Aug. . Stem 4 5 

 feet high, branched, pubescent. Flowers large, crimson, in 

 pendulous spikes. Naturalized throughout the whole U. States. 



**** Floicers in panicled spikes. Perianth 5-parted. POLYGO.MLLA. 



13. P. articidatum Linn. : stem erect ; leaves linear, obtuse ; stipules 

 short, truncate ; spikes paniculate, filiform, erect ; pedicels solitary, 

 articulate near the base ; flowers perfect, octandrous, trigynous, nod- 

 ding. 



HAB. Sandy plains. N. S. W. to Michigan. Sept. <jj). 

 Stem 12 inches high, branched above. Leaves very small, linear. 

 Flowers reddish-white, in spikes which are jointed by a suc- 

 cession of imbricate sheathing bracts. A singular plant which 

 should perhaps be separated from this genus. 



***** Flowers in racemose panicles. Leaves subcordate or sagittate. 

 FAGOPYRUM. 



14. P. sagittatum Linn. : stem prostrate, square ; the angles awned 

 with reversed prickles ; leaves sagittate, acute, nearly sessile ', flowers 

 in small peduncled heads, octandrous ; styles 3-cleft. 



HAB. Wet grounds. N. Y. to Flor. July, Aug. &.Stcm 



