I live in a neighborhood that has man-made waterways throughout the area. I happened to be out on my deck today and noticed a large mat of this plant in the water and I'm wondering what it is. I googled and found a photo of a plant named East Indian Hygrophila (H. polysperma) that sort of resembles it but I couldn't really find any close up pictures for comparison. Does anyone recognize this one?

Try Ludwigia palustris.

Yes, looks like Ludwigia palustris. It is a weed here, on the land, because of the high rainfall.

http://plants.usda.gov/core/pr...

http://plants.ifas.ufl.edu/nod...

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

Thanks so much Y'all ... so glad it's a Florida native and not one of the invasive plant species!!

It can be useful too! It's good medicine for treating respiratory ailments.

http://www.naturalmedicinalher...

http://plants.for9.net/edible-...