THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SECOND SERIES.] 

 No. 2. FEBRUARY 1848. 



VIII. — On Anacharis Alsinastrum, a supposed new British Plant. 

 By Charles C. Babington, M.A. ; with a Synopsis of the 

 species of Anacharis and Apalantlie. By J. E. Planchon, 

 doct. es sc* 



[With a Plate.] 



Before describing the plant to which this paper more especially 

 refers, it is desirable to state the reasons which have cansed the 

 adoption of the generic name Anacharis rather than Udora. By 

 the kindness of Sir W. J. Hooker I have had an opportunity of 

 examining the numerous specimens of plants referable to these 

 and allied genera preserved in his Herbarium in company with 

 my friend Dr. Planchon, its efficient Curator ; and I take ad- 

 vantage of this opportunity of acknowledging my obligations to 

 him for the very liberal manner in which he has placed his ma- 

 nuscript notes at my disposal. In Richard's Memoir upon the 

 Order Hydro char idece, where the genera Elodea and Anacharis 

 were characterized, only the male flowers of the latter are de- 

 scribed and figured. In the Herb. Hooker, there are male and 

 female specimens, collected byTweedie in La Plata, which agree 

 well with Richard's description of Anacharis (callitrichoides) taken 

 from Montevideo specimens of the male plant. They differ 

 from Drummond's Saskatchewan Udora (A. canadensis, Planch.) 

 by having petals to the male flowers, and their sheaths less in- 

 flated : it seems probable that this is the Elodea canadensis of 

 Michaux, who (or Richard) has apparently been misled to consider 

 it as of the genus Elodea by the very great resemblance of its fe- 

 male flowers to the hermaphrodite flower of E. guyanensis. Indeed, 

 in the absence of the males, the female flowers of some species of 

 Anacharis {A. Alsinastrum for example) might well pass for her- 

 maphrodite flowers from which the anthers had been accidentally 

 removed : the female flower of A. Alsinastrum differs from the 

 hermaphrodite flower of E. guyanensis (Rich.) solely by wanting 



* Read before the Botanical Society of Edinburgh, 9 Dec. 1847. 

 Ann. $ Mag. N. Hist. Ser. 2. Vol.i. G 



