One of the books… well actually two of the books… that I love to go through is A Modern Herbal by Mrs. M. Grieve.
This two book series covers a LOT of herbs. While I wouldn’t rely on it exclusively as a resource for doing herbal medicine with your family, it is a wonderful pair of books for adding to your medicinal plant knowledge. It was originally published in 1931, so it isn’t exactly “modern” anymore. However it is rich with information about how certain plants were historically used, their cultivation and spread.
For example:
Castor Oil Plant
This section includes, along with latin names, cultivation, uses, etc. information about how different societies use the plant, it’s affects in soap making, its industrial use, as well as medicinal uses.
Sometimes there are even stories and recipes to go with the plants.
Occasionally, when I can find no information about a plant anywhere else, I’ll often find at least a little in this pair of books.
This pair of books isn’t all that expensive either. Around $26 Canadian for the pair of them the last time I looked. A pretty good deal I think, considering all the information they contain.