Ozma of Oz (free online edition at Project Gutenberg).
There was also a lunch-pail tree with grew lunch boxes containing different lunches — each sandwich was wrapped in white paper and came with a pickle and lemonade.
Ozma was my favourite of all the Oz books. I especially love the way L. Frank Baum draws clouds and suns throughout the book. Maybe it is because he was from Kansas? You can listen to an hour-long interview with Baum's biographer Evan Schwartz here.