I have some in my personal pond and have not seen it on about 200 ponds I worked on this year. There is another similiar plant called penny wort, but mine looks just like 4 leaf clover and have not seen in any plant Id book. It is easy to control with 2% glyphosate app. I keep it in one corner with two applications/year. It is good cover since it is not as dense as some weed species.
