this is primarily directed toward Blast as he seems to know a great deal about using wild plants for food and other purposes. However, information from anyone is very welcome.

I travel extensively to various parts of the world. I have seen many similar types of plants and trees in many parts of the world. Is there a book, school, method or any other resource for learning about plants and their uses without focusing exclusively on a particular region? If a worldwide resource is not available, is there something which can be used for a broad region (continent, hemisphere)?

I appreciate all the help.