20 Rhodora [FEBRUARY 
last year and the previous one it had increased so rapidly as to require 
removal by manual labour: but the more it was disturbed the faster it 
grew. This year it covers the entire surface, and in so dense and 
wonderful a manner that no amount of labour seems capable of removing 
it, or even keeping it under. It actually grows faster than it can be 
cleared off, the mode of which is, first by cutting, and then by draw- 
ing it together by means of long rafts, collecting it on the shore, 
and either carting it away or placing it in heaps for decomposition.” 
In 1848, after this strange new waterweed had been found several 
times and sent to him twice, Babington! described it as Anacharis 
Alsinastrum. It has been stated repeatedly that this plant produces 
in Europe only pistillate flowers. In America it is said to produce 
perfect flowers. Babington, however, states that the female flowers 
have three subulate filaments, lacking anthers. Marshall? says, ‘‘it 
flowers in our still waters in the greatest profusion, covering the 
surface with its tiny blush-colored flowers and silky threads, but I 
have never found any but females. From the peculiar character of 
the female flower (by which I mean the fact that although there are 
no perfect stamens present, yet the filaments are always there, wanting 
only anthers to surmount them to make the flowers perfectly her- 
maphrodite), * * *." These flowers have been figured in European 
works, and their plan is 3 sepals, 3 petals, 3 bipartite stigmas, and 3 
filaments or staminodia. See, for instance, the beautiful plate in 
the English Botany? "The American literature is full of references 
to the staminate flowers of Elodea canadensis, but it seems clear now, 
that in every case this was due to a confusion with some one of the 
other species of Elodea, all of which do have distinct staminate flowers. 
It is true that Caspary identified with Michaux's material of Elodea 
canadensis some specimens from Bethlehem, Pennsylvania, C. J. 
Moser, 1832, which he says have 7 stamens and no stigmata. The 
writer feels confident that these specimens of Moser's belong to 
another species. To summarize, as Elodea canadensis Michx. occurs 
in Europe it produces pistillate flowers with 3 filaments or staminodia. 
All flowering material from America examined by the writer has 
exactly the same sort of flowers, pistillate flowers with 3 staminodia. 
1Ann. & Mag. Nat. Hist. II. i. 83 (1848); translated in Ann. Sci. Nat. Bot. 3rd 
ser. xi. 69 (1849). 
? Phytologist n. s. ii. 196 (1857-8). 
3 Smith, J. E. & Sowerby, English Bot. Supplement pl. 2993 (1865). 
