Combinations of multiple herbs guided by TCM theories, called Chinese herbal formula, are the major application form of Chinese herb.
However I will point out that gentle and uplifting supports which some find helpful in low-grade depression relief, such as exercise, certain herbs, counseling, guided imagery, relaxation, prayer, (or hey, even that unscientifically verified behavior of talking with a friend) don't have the side-effects of medication.
While the Guide herb(s) are applied to harmonize and integrate the effects of other herbs, or direct the formula to act on the target meridian or the offending part of body.
However, Guide herb(s) are not indispensable for a formula, based on the specific conditions, Guide herb(s) might be used or not used in a formula.
Scott Cunningham's Encyclopedia of Magical Herbs is an essential guide for the novice witch.
HERBS: The Complete Gardener's Guide (Firefly, paper, $24.95), by Patrick Lima, may make you think about turning your entire lawn over to herbs, particularly the gray-green artemisias.
Apps field guide to kitchen herbs.
There's also a complete guide to garden herbs (perfect for a farmers market) and finally, a tool to identify the hottest peppers.
There are many good books about using plants for medicinal purposes, such as National Geographic's Guide to Medicinal Herbs (2012), which details what does––and what does not–– really have healing properties.
They are commonly composed of one or several medicinal herbs following specific medical theoretical guides.
