CHAPTER IY. 
WATER TRANSPORTATION OF PLANTS. 
11. Some green buds and leaves float on water. — Loosely 
floating on slow streams of the northern states, in water 
not the purest, may often be found the common bladder- 
wort, Utricularia vulgaris, producing in summer a few 
yellow flowers on each 
stem, rising from six to 
twelve inches above the 
water. The lax, leafy 
branches in the water 
are from six inches to a 
foot long. The leaves, 
or thread-like branches, 
are about half an inchs 
long, more or less, and 
several times divided. 
Scattered about are 
large numbers of flattened scales, or bladders, sometimes 
one-sixth of an inch long, which give the plant one of its 
names. For a long time the bladders were thought to 
serve merely as life-preservers ; it was supposed that they 
were constructed to keep the plant from sinking to the 
bottom. In reality these bladders help preserve the plant 
Fig. 11. — A free branch and two buds of 
bladder wort. 
