Everyone knows that trees have minerals. Imagine the orange tree. The bananna tree. Or, the tree which gives us brazil nuts - high in selenium. When I burn wood, I get ash, which is largely comprised of the carbonates of various metallic elements, which some interpret as minerals.
The discussion related to iodine, and I have no idea why anyone would see my position on Iodine as extending to all minerals. It would be ridiculous to state that trees don't have any minerals.