Fragging a toadstool mushroom
 

I was wondering if you can just cut the stalk of the mushroom and attach it to a rock. Will the remaining piece grow a new head?

Good question. I'd like to see the answer to that one.

Yes with both Sarcophyton and Corallimorphs any small amount of tissue left behind has the ability to grow into a new colony.

Yup very resourceful they are even if you scrub the stump it should grow back:):)

So can you trim a little tissue off the edge of one to propagate? Any toxin danger?

Yea you can, you can snip anywhere Ann's it will rwgrow I just use elastic band to secure to a disk Ans it heals quickly.shouldn't cut leathers in your tank they will shed immediately after. If you must just run carbon afterwards:) after dragging it's important tjatthe water usclean to speed up recovery:)