Plant turned brown & slimy

[TurboTheBetta]

Hello all,

For the past few days I’ve been monitoring this one plant in my 34L aquarium - that houses one Male Betta fish. Over the course of a few days it’s gradually been getting darker in colour with some leaves falling off and floating around the aquarium to which I would have to fish out.

Today it was the worst it’s ever been. So I removed the whole of this plant out of the tank. The plant was falling apart and I noticed the roots had turned a blackish brown colour; I’ve been using fertiliser spray etc in the tank and the other planted plants are doing well but this one I believe has died?!

Pictures attached show the plant, leaves and roots that are black / brown and slimy. Just looking for advice really I’m new to this hobby…please also note this plant was placed at the back of the aquarium it was getting same amount of light as the others and also fertiliser daily. However, it was placed right next to where the heater was.

Thank you!

 

[connorlindeman]

What type of plant is it?