The study compared different wetland plants to see which ones are best at cleaning nitrogen and phosphorus from polluted water. They tested 13 plants and found that some, like yellow iris and Cyperus alternifolius, were very effective at removing nitrogen, while others, like Irispseudoacorus and Scirpus tabernaemontani, were good at removing phosphorus. These plants could be used to clean up eutrophic water in wetlands or for landscaping.