264 CERATOPHYLLACE^E. [Diclinous Exogens. 



inferior radicle is with most oi' the Urtical Alliance. Such .being the case, it seems to 

 me that until some better suggestion shall have been offered than that of stationing 

 Hornworts near the Gymnospermous Conifers, they may be regarded as anomalous 

 plants of the Urtical Alliance. 



A singular view is that of Dr. Asa Gray, who would place Ceratophyllum near 

 Nelumbium, because of its highly developed plumule, for it would be difficult to point 

 out any other resemblance ; to this opinion he has been led by the account of the 

 development of the embryo given by M. Adolphe Brongniart Ann. Sc. 12. 253, which 

 is only in part correct. 



Found in ditches in Em-ope, North America, Northern Asia, Senegal, Barbary, and 



These plants have no known use : they have sometimes the heavy smell of Chara. 



GENUS. 



Ceratophyllum, L. 



Numbers. Gen. 1. Sp. 1. according to Schleiden ; 6 according to Chamisso. 



Chenopodiacece. 



Position. — Urticaceac. — C'ERATOPHYLLACEiE. 



Haloragece. 



