Worlds best aquariuum filter. Look what it does:

Removal capacity of faecal pathogens from wastewater by four wetland vegetation: Typha latifolia, Cyperus papyrus, Cyperus alternifolius and Phragmites australis


Umbrella plant

Probably the easiest plant to grow, ever, in water or soil. Can be started from a single leaf quite easily, just put it in water in a sunny place. When large they make an excellent aquarium filter just put a plant in a bare tank, cover with gravel and add water. Must have strong light, sunlight is best.

Here's a good write up on how to grow Cypereus.


Papyrus: Where paper comes from