JUNE. 187 
This curious plant may now be found on stagnant waters, 
and though unheeded by most people is of so singular a 
construction that I advise the young botanist to examine it 
carefully. I quote Hooker’s description of the genus. It 
will be seen by this account that these plants have apparently 
only a flat leaf and roots proceeding from it ; for the flowers 
are so inconspicuous that they are seldom observed, though 
the anthers rise above the water during the flowering season, 
and may be seen if closely examined. One species, 
Lemna potyruiza. Greater Duckweed. Though fre- 
quently seen on our ponds has seldom been found in flower 
in England. It has a larger leaf than the rest. The common 
species, 
Lemna minor, Lesser Duckweed, is found on most stag- 
nant waters, affording food for ducks, and shelter for insects 
and mollusca. The frond, or leaf, is nearly round, thick, 
and succulent, slightly convex beneath, with the roots 
hanging from them. Another species, 
Lemna trisuLca, Lvy-leaved Duckweed, is easily known 
from the last by the different shape of its leaves, which 
are long instead of round, and thin in substance. 
Lemna erp, Gibbous Duckweed, is not very common ; 
