As the binomial implies, this species is mostly associated
with wetlands (Figures 1 & 2). While there are forms that
are also cultivated in uplands, the wild plants are in waterways,
such as canals, lakes, ponds, rivers, and in marshes
and paddies with rice (e.g., Austin 1980, Fang & Staples
1995, van Ooststroom & Hoogland 1953). The fruits
are tardily dehiscent or perhaps even indehiscent, and are
presumably adapted for water dispersal. Like many others
in the family, I. aquatica has “labyrinth seeds,” retaining air
pockets that allow them to float for long periods (van Heel
1970, 1971). Several members of the family are famous
for being dispersed by water (e.g., Guppy 1917).