A bright chrimson red crustose lichen - if this lichen isn't used for pigment then it should be. It stands out in a forest making it easy to find. I found several examples of it on a variety of tree species. Pyrenula cruenta has a fruiting body called perethecia. With most perethecial lichens (P. cruenta included), the spore producing mechanism is contained inside a cavity which has a tiny opening to the outside called an ostiole. When mature spores will be ejected through this opening.
Spotted along the Backcountry Trail of the Gulf State Park.