172 OCTANDRIA.— TRIGYNIA. 



HAB. Wet places. Aug.— Oct. U . Stem lift, 

 high ; ft. wh. — plant acrid. 



6. P. mite : flowers octnndrous, somewhat crowded : 



styles 3-parted ; leaves narrow-lanceolate, some- 

 what hairy ; stipules hairy, with long ciliae. 

 HAB. Wet places. Aug.— Sept. U . Stem 18 in, 

 high, ft. pale red or white ; plant not acrid. 



7. P. virginianum : flowers 4-cleft, unequal, remote, 



pentandrous ; styles 2 ; spike very long, virgate ; 

 leaves oval-lanceolate. 

 HAB. Moist shady places. Aug. — Sept. If. Stem 

 2 — 4 ft. high, ft white ; fr. birost. 



8. P. amphibium : flowers pentandrous ; styles bifid ; 



spike oblong or ovate ; leaves petiolate, oblong or 



lanceolate, subcordate. 

 x. terrestre : stem nearly erect ; leaves oblong-lan- 

 ceolate, often cordate at the base, smooth above, 



slightly pubescent beneath ; spike ovate-oblong. 

 HAB. Borders of ponds. Aug. lj. . Stemassurg.. 



8 in. high ; spike bright rose-col. 

 a. aquaticum : leaves floating, ovate-lanceolate : 



spike cylindrical-oblong. 

 HAB. Floating in lakes. Aug. U. Stem 3—10 



ft. long r branch. ; ft. rose-col. 

 ). P. pennsyhanicum : flowers octandrotts ; style 2- 



cleft ; spike oblong, crowded ; peduncles hispid ; 



leaves lanceolate, slightly hairy ; stipules smooth 



and naked. 

 HAB. Fields, and along ditches. July — Oct. 



Stem 2 — 4 ft. high ; feav. pale gr. ; ft. red. 



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

 spikes oblong, rather crowded, erect ; peduncles- 

 scabrous ; leaves ovate -lanceolate, on short pe- 

 tioles, hoary. 



HAB. Wet places. Aug. ©. Stem 2— 4 ft. high, 

 leav. pale green. 



11. P. Persicaria : flowers hexandrous : styles bifid: 

 spikes ovate-oblong, erect ; peduncles smooth : 

 leaves lanceolate ; stipules smooth, ciliate. 



HAB. Low grounds. July — Aug. 0. Stem 1 — 2 

 ft. high ; spikes dense, rose-col. 



