49 

 WATERLETTUCE 



BOTANICAL 



Waterlettuce (Pistia stratiotes) is a floating, semitropical plant 

 limited to the Gulf region. Generally, it is much less abundant 

 and important than its frequent associate, waterhyacinth. How- 

 ever, there is growing need for information on how to control 

 waterlettuce since it is less susceptible to 2,4-D than water- 

 hyacinth and its beds tend to spread in places where water- 

 hyacinth has been killed. Water solutions of 2,4-D, such as are 

 used in waterhyacinth control, are not effective on the velvet- 

 surfaced leaves of waterlettuce. Consequently, oil carrier is 

 required. 



