TRIANDRIA MONOGYNIA. 295 



others setiform ; leaves ovate, on long petioles, serrate. 

 HAB. On mountains. August,^. Much branched, and almost wool- 

 ly ; Jl. pale blue, spotted with purple ; upper Up very short. 



12. SAL VI A. 



S. lyrata : radical leaves lyrate-sinuate ; stem nearly leafless, retrorse- 



ly hairy ; upper lip of the corolla very short. 

 HAB. Fields and borders of woods. June, 7J-. Stem afoot high, very 



hairy ; whorls about 6-Jl. ; cor. blue. 



13. COLL1NSONIA. Horse-weed. 



C. canadensis: leaves broad-cordate, ovate, glabrous; teeth of the ca- 

 lyx short, subulate ; panicle terminal, compound. 



HAB. Among rocks, in rich soil. Aug. Ij.. Smooth ; leaves on long 

 or short foot-stalks ; Jl. dull yellow. 



14. CIRC^EA. Enchanter's nightshade. 



C. lutetiana b. canadensis : stem erect ; leaves ovate, remotely tooth- 

 ed, opaque, nearly smooth. 



HAB. Shady woods. July Aug. 1].. Stem I 2 feet high, simple ; 

 Jl. in racemes, pedicellate, reddish white ; fruit hispid. 



C. alpina : stem branched, very smooth, often procumbent; leaves 

 broad cordate, membranaceous, acutely toothed, shining. 



HAB. On barks of trees and wet mossy rocks. Aug. TJ.. Very smooth, 

 68 in. high ; leaves very broad, subdiaphanous ; fruit pubescent. 



15. LEMNA. Duck's Meat. 



L. trisulca : fronds thin, elliptical-lanceolate, caudate at one extremity, 

 at the other serrate ; roots solitary. 



HAB. Pure stagnant waters. . Fronds laterally proliferous, and 

 appearing cruciate ; root a solitary fibre, calyptrate at the extrem- 

 ity. 



L. minor : fronds nearly ovate, compressed ; roots solitary. 



HAB. Stagnant waters. . Fronds a line or a line and a half long, 

 succulent, aggregated. 



L. gibba : fronds obovate, nearly plane above, hemispherical beneath ; 

 roots solitary. 



HAB. Stagnant waters. <v). Fronds as large as the preceding, gib- 

 bous, pellucid and reticulated beneath. 



TRIANDRIA. 

 MONOGYNIA. 



Genera. * Fl wcrs superior. 



16. IRIS. Cor. incomplete, 6-parted; 3 of the segments reflexed, the oth- 

 ers erect or connivent. Style short, or 0. Stig. 3, petaloid, covering 

 the stamens. Caps. 3-celled, many-seeded. 

 26* 



