I came upon this book by chance. I was just leaving the library when I noticed Plant Families on display, and it jumped out at me. (I mean visually - it didn't leap off the shelf.) I looked at a couple pages, and it was so captivating, I had to go back to the counter and check it out.
The cover is beautiful, the inside cover likewise. The pages are beautifully illustrated and perfectly arranged. The paper itself is of superior quality and so lovely to touch, and a vivid red silky ribbon bookmark completes it. The entire thing is a work of art. If you ever have an opportunity to browse through this book in person, I highly recommend it, for its artistic merits alone.
I have an interest in plants, but I'm not a gardener or a botanist. Being merely a curious person who appreciates plants, the information in this book has little practical use for me personally, but I did learn a lot from it! (I had only meant to look at it, not read the whole thing, but it was so interesting that I read the whole thing after all!)
I have seen some reviews point out that this book is more geared towards Europe, and is a bit lacking with respect to North American species. I am not knowledgeable enough to judge the accuracy of this claim, and I would assume that gardeners know what they're talking about, but I found that the book talked about plants across ALL continents, with North America getting as much attention as the rest. It may be that people are objecting to the fact that this book talks mainly about plant families, and only lists individual species as examples of what belongs in a plant family - but the examples seem to be about an equal mix from all continents (I've looked up a lot of them, and they are from all over).
Anyway, the purpose of this book is not to be a comprehensive encyclopedia of each individual species of plant. What it was meant to do - and does very well, in my opinion - is to clearly delineate plant families, and provide easy-to-understand explanations (with very helpful illustrations) of how to recognize plants as members of various families. It also talks a little bit about the needs of various types of plants, and what is suitable to grow in what kind of environment, but again, it doesn't go into great detail, since that's outside the scope of the book.
Plant Families is perhaps not the most comprehensive book on botany, but I think it is a great introduction to the plant kingdom, and useful as a starting point for finding out what type of plants you are interested in, which could be very helpful in narrowing down what additional books would be useful towards that particular interest. Or you could simply appreciate the book as a work of art.