What weeds are similar to water hyacinth?

Question

What weeds are similar to water hyacinth?

Answer 1

Pistia is the closest to Eichhornia (i.e.  Water hyacinth) in its Nuisance value .

Next is Typha and Lemna .

Others are wolffia and Azolla

All the above mentioned plants are similar to each and to water hyacinth   as all of them require plenty of water to grow and all of them are encroachers and threat to crop plants and water resources!!! ( Similarities practically end here !. They are dissimilar in many other respects that are not covered by the question )

More Info. on the links -

http://en.wikipedia.org/wiki/Eichhornia

http://en.wikipedia.org/wiki/Pistia

http://en.wikipedia.org/wiki/Typha

Answer 2

Eichornia is similar to water hyacinth.