It was somewhere outside Barstow when wrote:

So I'm wondering what other unusual woods have been used, by whom, for
what?

Laburnum. It's a fairly common garden shrub in the UK, grows to 4"
diameter and has very dark heartwood. In the 18th century it was used
for "oyster veneering" - diagonal ovals were sawn from the branches,
trimmed to rectangles and then laid as a tiled veneer. Looks hideous
IMHO, but it's an interesting effect. Nicer to my eye if you make
small boxes with a plinth and capital moulding to them in plainer
maple, then use these oysters as a frieze between them.