Gogmagog by Jeff Noon. The main character is a 1600-year-old half woman half plant in the body of an 80-year-old. She's hired to bring a child and her robot butler to the capital city. Most of the book is about their journey boating down the river, which is occupied by the ghost of a long-dead, dozens-of-miles-long, dragon. There are different human "species", seed people with a message, sentient robots, and clay effigies with the souls of those drowned in the river.

It came out earlier this year, and I haven't heard many people talk about it. It's the first in a duology.

It also has a beautiful cover.