Well, Eichhornia crassipes is no exception. Yes, Eichhornia crassipes is a weed. Even though it produces a stunning purple bloom, it can be quite a nuisance, so much so that possession of it is illegal in some areas of the United States.
Water hyacinths look similar to orchids floating on water.
They float because their shiny, green leaves have bulb-like structures beneath them that contain air pockets. The water hyacinth's illegality is due to its ability to reproduce asexually very quickly. A high reproduction rate means that many plants are growing within a small area of water all at the same time, causing the clogging of waterways, which results in navigating dilemmas, flooding, and crowding out of native plant species. The water hyacinth is not itself native to the areas where it causes so many problems. It originated in South America in the Amazon River Basin, but it can thrive in any sub-tropical or tropical climate.