This is another oak burr from a Lancaster tree that came down in a storm. (no surprise there).
The surprise is that the entire middle of the burr was completely rotten, leaving me with a rough looking piece of wood that had a whole in the middle and a steeply sloping face.
So! Thinking cap on.
Put an Orchid in it! Orchids grow on trees. Viola!
Lots of sanding and a little machining and hey presto! What a little beauty.