I got a new piece of LR yesterday and one pice has what looks like a small xenia branch...It is really small and hard to take a pic of but it looks like a branch off one of these
its definatly not aiptasia...had one in my 90g (came on some chaeto). something ate it...It looks just like a branch of xenia...ill try and take a pic right now.
Waiting on that picture. It does sound like a clove polyp. Xenia isn't a single stalk as a rule. It is like little clusters at first.
Spanko is the expert. i am just guessing.
in my old tank my xenia just about died off. all that was left was a very small little stock. Now it finally grew back into a very thick mat about 1/2 inch tall. There are a few different types of xenia. The one in your pic grows like crazy and gets like 4 inch stocks. It does in my tank anyways.
on the right side is my bush type xenia Attachment 221467
and you can see my pulsating xenia thats just about taking over the tank and started from 2 little tiny stocks Attachment 221468