This book is mostly what it says on the tin, anecdotes about Magdalena's travels seeking out the world's most endangered plants, and his subsequent conservation efforts to stave off their extinction.
It starts off a little rocky, as my first impression of Magdalena was more evangelical than messianic, and the mini-biography at the start sometimes ventured into very self-satisfied prose. The biographical information was helpful, though probably could have been edited a bit.
Once chapter 2 begins though, all of that is quickly forgotten. As someone who is deeply interested in conservation of both plants and animals (except roaches), I was enthralled as I read about efforts to save species plants on Mauritius and Rodrigues Islands, in Bolivia, and Australia (water lilies!). As the daughter of an orchid grower who very often had to MacGyver solutions for tricky breeding problems, I genuinely enjoyed the parts where he had to think on his feet, or think outside the box to overcome perceived roadblocks to cultivation.
There's no denying his enthusiasm and his passion for his work; neither is there any denying the need for it, in a world where 2000 unknown plants can be identified in a given year, only to have many of them go extinct before they can even be named. I learned a great deal reading this, and hesitated to put it down, always wanting to know where he was going next and what he'd find when he got there.