In the Dec. 21 article, "New weed poses major Delta threat," an opinion is given that an official action is required to limit the spread of sponge plant.
West Indian sponge plant or amazon frogbit (Limnobium laevigatum) is widespread in America. It has been observed in the wild in Europe, but did not naturalize so far. It can be found growing wild in lakes, ponds, and slow rivers all over Central and South America. Its floating and fast growing nature does not support the ideas to use it as ornamental plant in back yard pond, specially in regions, where it has not yet been present. Easy care in aquarium, but difficult when it escapes.