THE ANNALS 
AND 
MAGAZINE OF NATURAL HISTORY. 
[SECONB 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 Apalanthe. 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 caused 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 thi^ 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 Hydrocharidece, where the genera Elodea and Anacharis 
were characterized, only the male dowers of the latter are de- 
scribed and dgured. 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 Saskatchawan Udora (A. canadensis, Planch.) 
by having petals to the male flowers, and their sheaths less in- 
dated : 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 dowers to the hermaphrodite dower of E. guyanensis. Indeed, 
in the absence of the males, the female dowers of some species of 
Anacharis (A. Alsinastrum for example) might well pass for her- 
maphrodite dowers from which the anthers had been accidentally 
removed : the female dower of A. Alsinastrum differs from the 
hermaphrodite dower 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. 6 
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