Celtic Astrology, Druid Tree Signs by Phyllis Vega
This book reintroduces an ancient system of astrology developed by the ancient Druids through a mystical runic alphabet known as the Ogham. No prior knowledge of astrology is necessary to use this system; all you need to know is the day and month of birth to greatly enhance the interpretation of your natal chart by adding your tree sign and the new information it conveys.