Pistia stratiotes L., is well known as water lettuce or 'kiambang kecil', belongs to the Araceae family. It is a monotypic genus. This free-floating plant aquatic distributed in tropical and sub-tropical country worldwide. It has been used in various purposes such as ornamental water plant, medicines (for the treatment of eczema, leprosy, ulcers, piles, stomach disorder, throat and mouth inflammation, a few to mention), bioindicator, bioremediation, purification and forage. On the otherhand, this species is quickly spread and form a dense mat that can cover an entire body of water thus can have negative impacts on native aquatic plants and fish. It is also host of mosquitoes.