Brown rock cover

[Sullyman]

What are these brown things that I've got growing on a couple of rocks? They need light and are spreading. What are they and what can do to keep them in check. No tubes but they can close up, almost disappear when they want to.

 

[menard]

Bob
Pachyclavularia , same member as your GSP. Invasive, so you know how that goes.

 

[Sullyman]

Thanks Menard, they don't have the ball shape in the middle like gsp, they look more like the polyps from the pipe organ but no tubes.
I'm going to have to prune/nuke them back, they're taking some prime real estate up and aren't slowing down. Anything that would eat them would probably eat stuff I value, so I guess a little napalm/kalk will be needed to get them to retreat.