Didn't some say that when they had specks sent away they were identified as carbon? I just looked up mulch fungus/bacteria and read this:
Wood and bark, as organic matter, decompose over time. Bacteria and fungi are involved in the decomposition. These organisms derive their energy for growth from the carbon-based compounds found in wood and bark. Both bacteria and fungi are microscopic, but fungi may be visible. Landscape Mulch Fungus
Lamb, I believe you had posted a video about this fungus. They say it is tar like and I can say that I have found stains in my house and on our socks resembling tar that do not come out in the wash.
I am now 100% convinced this is the black stuff in my son's bedroom furniture. As the video said, and another website, this stuff embeds in wooden decks, the outside of cars, house siding etc. and that it takes the finish with it. My son's bedroom furniture was new a little over a year ago and there are spots where the finish is missing and there are black spots embedded in the finish.
The artillery fungus "shoots" its black, sticky spore mass which can be windblown as high as the second story of a house. The spore mass sticks to the side of a building or automobile, resembling a small speck of tar. They may be found on the undersides of leaves on plants growing in mulched areas. Once in place, the spore mass is very difficult to remove without damaging the surface to which it is attached. If removed, it leaves a stain. A few of these spots are barely noticeable, but as they accumulate, they may become very unsightly on houses or cars. To date there are no known ways to manage the artillery fungus.