Reddit reviews Masdevallias: Gems of the Orchid World

Rhttps://www.amazon.com/Masdevallias-Orchid-World-Mary-Gerritsen/dp/0881927376

I haven’t gotten very far into this book, but it does have a fair amount of info on the historical discoveries in the genus and it’s certainly a niche book. It, of course, does have car info too. Not sure it’s what you’re looking for but may be worth checking out!

Also, not books but you may be able to find some more scientific reads over on Google Scholar- a review paper on a groups evolution may be easily found and for your bill as well.