Water LettuceSam Wiernusz

Characteristics

Water lettuce (Pistea stratiotes) is a floating plant. It looks like an open head of lettuce suspended on the water. Its leaves are thick and its roots are feathery.

Water Lettuce

• Perennial• Obligate species• Lives in temperate

climates worldwide• Form dense mats that

stretch from shore to shore

The Problem

• Clogs waterways• Degrades water

quality• Greatly reduces

biodiversity

Water Lettuce

• Found globally, but its spread is limited by severe cold

• Leaves will regrow after moderate freezes

• Still sold through aquarium supply dealers because it is not labeled a noxious weed yet

Source of Introduction

It is debated among scientists as to whether or not it is native to the United States. There are records from 1765 of this plant being observed in Florida. Some experts believe, however, its origin is from Africa.

Control Measures

• Mechanical harvesters and choppers• Bio control insects• Aquatic herbicides

Questions?