Weired spikey plant?

[Mjpendrey]

Anybody know what these are? They look like plant matter to me they are growing everywhere in my tank and are brownish green! They grow and pop up from nowhere they look like pointy little tubes and some have buds in the middle like they are gonna dart branching off, sorry pics are crap!

 

[Mjpendrey]

The first pic it the little bunch of brown things dead centre of pic growing diagonally out of te rock and the last two pics is the biggest I have it's growing on its own down the bottom and is the green brown pointy thing in the middle. If you look down I also have a white thing growing looks like a plant again lol that's made of thin white string but at the ends it gets bulbous and moves around like it hitting something its deffo alive as if I tap the glass all the arms shoot together?