Ee 
ae a ee! Re Fe) eS ae, Se eee ee eT 
fig. 9 the fully 
1899 ] LIFE-HISTORY OF LEMNA MINOR 45 
the outside of this flower is the beginning of the spathe (e), 
which grows up about the other floral organs. This spathe 
when fully formed is usually one cell in thickness, though rarely 
it is two-celled at the base. It grows rapidly and soon extends 
beyond the edge 
of the frond (fig. 
1, f), becoming 
the only means of 
detecting the pres- 
ence of flowers 
when one is un- 
aided by a magni- 
fying glass. In 
formed spathe is 
shown as it sur- 
rounds the carpel 
and stamens. 
Fic. 9. Flower-spathe enclosing carpel and two sta- 
mens; ovule seen in carpel. X 73. 
The stamens Fic. 10. Carpel with ovule; stigma region of carpel 
appear at first as shown. X 260. 
one small protuberance extending in the plane of the surface of 
the frond (fig. 8). As this 
projection becomes longer 
it branches, each branch 
later becoming one stamen. 
One of these branches is 
always less prominent and 
less advanced than the other. 
In adult stamens the single 
row of trachee (fig. 11) of 
each filament is seen to have 
= a. stamens of one flower. originated from a common 
ieee bundle at the region of 
branching (fig. 2 2). When the stamens are mature the anthers, 
the loculi of which lie in one plane, are pushed out beyond the 
margin of the Spathe by the rapid elongation of the filament. 
I. Longitudinal section of part of 
howing single row of trachee, 7. 
Fic. 1 
filament, s 
X §20. 
