Plant ID

[Martin]

Does anyone know what this plant is? I bought it (only 1) a while ago for around $8 and it grows like crazy. I've always felt guilty throwing out clippings, because I feel like I'm wasting what I throw out, so whenever I clip it I replant the clippings. Unfortunately this has led to it completely overtaking my 46 gallon. I'm hoping I can trade them or sell them, as I want to restock the tank.

[lucius]

Looks like guppy grass.

[Black_Rose]

I agree, guppy grass.

[tanksalot360]

I see a stem...
Might be a Pogostemon, maybe P. quadrifolius