Pistia stratiotes
ζPistia stratiotes L. ζ(water lettuce), an aquatic, native to most tropical and some subtropical regions, free-floating and resembling a lettuce, has been introduced and dispersed for horticultural purposes and has appeared in the wild state in the northern half of N. Id. First recorded by Healy (N. Z. Weed & Pest Control Conf. Proc. 28, 1975, 282).
