A Short, Sharp Shock

Some wild world building, from geology (a long spine with ocean on both sides) to flora and fauna - and both (a group of people with trees growing from one shoulder - and one outcast with a tree on his opposite shoulder!). While I may think about the world, I won't consider much for the plot - it's more a series of interludes. I also may never look at nude women and cats the same way again...

In a mirror (which shows the truth?) there is a hint that the protagonist is a space traveler. Other than that, this is hardly science fiction or fantasy. It *is* weird. This short book (novella?) was released in 1990, before the authors well known Mars trilogy. I'm not sure how it ended up on my reading list. Down deep, I didn't love it.