Guess it all depends on how big the pocketbook is! I have one purse that could hold Michael Dirr's Manual of Woody Landscape Plants!
Probably what will help you most is something like Simon & Schuster's Guide to Garden Flowers
https://www.amazon.com/dp/067146678X/
(sorry about the long url) or maybe this one:
https://www.amazon.com/dp/0671222473/ which may be more comprehensive in a concise package.
These are the same size as their insect guides--too big for a pocket, but good for a purse. 4" x 7" x 1 1/2" thick.
Or, try: The Flower Expert by D. G Hessayon
https://www.amazon.com/dp/B007SRWFS8/
There's a whole series, and they are all a good size to carry to a garden.
All of these have good photos and drawings.
My problem with using the smart phone in the garden is, I can't read the screen in full sunlight. Maybe the next upgrade will have an improvement on that...
Hope that helps!
