That's not a mushroom. That's another species of lichen. Can you give us a close up picture of some of the leaves still on the tree, a picture of some fine twigs still attached to the tree, and a picture of where the tree enters the ground?

Roots go out, not down and yes, those roots grow wide. There is often a comparison to the root spread diameter to twice the height of the tree, but that is not hard and fast. Sometimes they will be more restricted and at other times could spread much wider - it is all in response to nutrients and moisture availability. And to any obstructions in their path. Thuja plicata, western red cedar, is native to the PNW and there are many very venerable and very large specimens in gardens all over, even in the heart of the city. As they age, they often produce a quantity of large surface roots, to the bane of many lawnmowers :-) As ken noted, roots are not a threat to a stable and secure foundation, especially in most of the PNW where soil subsidence is not an issue. They can and do lift slabs and patios or driveways, however.

Posted by poaky1 6 Pa (My Page) on Wed, Oct 1, 14 at 23:32 Bonsai is too difficult for me. I like them lush and ...

Oh this is not a fig from last year, it's a fig that grew on last year's wood (a breba fig) so it's part of the early crop. I don't get many of those on my trees, but they help stave off fig cravings until the main crop comes in LOL... this particular one actually looks very nice and fresh... yup, I'm driving home in about an hour and going straight to the fig tree to pick it.