Wow it could be a number of things. Retala Indica popped into my mind as I saw tips but theres no red and it's way too long. I wonder how it's going to grow.
My honest bet is erio. type II or some type of Eriocaulon sp. If those get longer it may be Erio setaceum, type II or III hahaha.. Hard one sorry I'm not of more help.