ABSTRACT
Common Names Water lettuce, floating lettuce, shell flower
Plant Description A monotypic genus, Pistia stratiotes, is a widespread aquatic perennial of the tropics, and has become a noxious weed in many lakes and waterways. With 6 inch (15 cm) leaves arranged in a rosette like a lettuce head, the plant floats on water with the assistance of the spongy air-filled base of the leaves. The plant reproduces via rosettes that connect to the parent plant. The arum-like flowers are inconspicuous, as they are enclosed in a leaflike spathe (Figure 316).
