sippURis. MONANDRIA. MONOGYNIA. S 



years since by Dr. L. C. Beck, a gentleman to whom I am 

 under many obligations for his valuable contributions to this 

 work. From a careful comparison of the American Hififiuris 

 with numerous specimens of H. -vulgaris of Europe, I have 

 little doubt of their identity. The former has, according to 

 the observations of Dr. Beck, pretty constantly eight leaves in 

 each whorl, though Michaux describes it as having six. 

 Pursh remarks {Fl. 11. p. 774) that he compared speci- 

 mens of Hififiuria vulgaris from Hudson's Bay, with the 

 European species, and found them entirely distinct. Are 

 there two species of this genus in North-America ? 



ORDER II. 

 D I G Y N I A. 



3. CALLITRICHE. L. 



Calyx inferior, 2-leaved. Corolla o. Capsule 2- 

 celled, 4-seeded, compressed. Gen.pl. 17. Nutt. 

 Gen. I. p. 3. Jiiss. p. 19. Roem. y Schult. 

 Gen. 39. Lam. Ill t. 5. Nat. Ord. Naiades. 

 Ju s s. Leaves opposite, flowers axillary, sometimes 

 monoicous, " seed 4, naked." Smith. Nut tall. 



Water- Chickweed. 



1. C. vtrna 0, intermedia Willd.: upper leaves spa- 



tulate-obovate, inferior ones linear, obtuse, and emarginate ; 



flowers polygamous; margin of the seed obtuse. Willd. 



Enum. H.Berol. I. p. 8. Ro em. i^ S c hult. ]. p. 46. 



C aquatic a Big. Bost. p. 2. C. heterophylla Pursh Fl. 



I. p. 3. Elliott Sk. 1. p. 46. C. ver7ia Mich. Fl. I. 



p. 2. Muhl. Cat. p. 1. Walt. Car. p. 69. 



Root annual, fibrous. Stefrt floating, composed of two tubes, 

 nearly simple, in deep water sometimes two or three feet long. 

 Leaves two to each joint, the uppermost ones crowded into a 

 stellated tuft, obscurely 3-nerved, the lower ones gradually be- 

 coming narrower till they are quite linear. Flowers solitary, 

 the uppermost ones stameniferous, the middle ones perfect, and 

 the lowest fertile ; calyx (corolla, L in. &c.) white, leaves lan- 

 ceolate, as long as the germen, but shorter than the ripe cap- 

 sule. Stamen 1 ; (rarely 2 ;) JUament as long as the germen ; 

 anther oblong, didymous. Germen quadrangular, compressed 

 and emarginate, twice as long as the subulate styles : capsule 

 2-parted ; seeds oblong. 

 Hab. Very common in shallow waters, stagnant or flowing. 

 April — August. 



