Water lettuce

Floating Leaf Plants

Pistia stratiotes:

Water lettuce

Pistia stratiotes L.: Water lettuce, water bonnets. Araceae (arum family). 

Perennial, possibly exotic. This floating, unattached plant consists of a large open rosette, 18 in (45 cm) or more in width, made up of coarse leaves and numerous feathery roots; it produces horizontal stolons that give rise to daughter plants. The light- to yellow-green leaves are stalkless, and wider at the blunt to slightly rounded top than at the base. Leaves are covered with short, dense, velvety hairs; parallel veins run down the leaf in shallow grooves, giving the leaf a striped or rippled look. Inconspicuous flowers are borne centrally in a leaf-like structure. This plant can increase rapidly in numbers and biomass, becoming weedy over large areas; it causes major problems with water flow and water use in lakes, rivers, and canals.