794 The American Naturalist. | September, 
always appear above water, and consequently it occurs only 
upon rather shallow shores. 
The Lemnacez are represented in the lakes by Lemna tri- 
sulca, L. minor and Spirodela polyrhiza, none of which make any 
attempt to grow in the bog. 
Eriocaulon septangulare is one of the few plants that are com- 
mon to the lake and the moor, in fact, it is about the only one. 
Whether it grows upon sand in a few inches of water, or upon 
the soft mud in the newest portions of the moor, it seems 
equally at home. I have found it growing in four lakes in the 
county, but never saw it in a swamp where there was no lake. 
Paine says (Cat. of Plants of Oneida Co.), of the distribution of 
this plant, “ Lakes and ponds of the north woods, throughout 
and common.” I conclude, therefore, that the plant is, in this 
region, a lake plant. 
Heteranthera dubia is a deep water plant, and grows in these 
lakes as well as in slow flowing streams. 
The whole order Nymphæaceæ is a water-loving group. With 
rare exceptions it is confined to the shallower portions of the 
lake. The exceptions are cases where the strong rootstock of 
Nymphxa and Castalia have persisted after the moor has ad- 
vanced into the lake beyond them and sends up, for a few 
years, its leaves and flowers through the thin turf. The con- 
trast between the -black mud of the moor and the pure white 
flowers of Castalia is very striking. Brasenia purpurea, Cas- 
talia odorata, Nymphæa advena are the representative plants. 
The depth of water in which these plants grow ranges from 
one to six feet, only rarely going outside these limits. 
Myriophyllum spicatum is a well-known aquatic finding @ 
place here. 
The Lentibulariacee is represented by two species in the 
lakes and several others in the moor. None of its species are 
common to both lake and moor. Utricularia vulgaris and U. 
minor are the lake plants. While occurring in other places, 
they thrive particularly well in the muddy lakes surrounded 
by moors, 
And, finally, for the order Compositz, we have, in our lakes, 
a single representative in Bidens beckii. : 
