Plants have long been used for food and medicine, but one use I find interesting is in magic. The Medieval Garden Enclosed, which is the blog of the gardens at The Cloisters museum, has a great post on two plants with magical uses. The museum's gardens divide plants according to their most common uses during the Middle Ages, and they have a bed devoted to plants believed to have magical properties.
There are many plants I admire and respect for their magical properties. My favorites include the oak tree (my maiden name, which is a Basque surname, means 'stand of oak trees'), hyssop, lavender, and rose. Not surprisingly, a number of tarot decks feature magical and medicinal plants in their artwork and symbolism. Johanna Gargiulo Sherman created the Sacred Rose Tarot, and the back of the deck features four rose mandalas encircling a central rose. Aeclectic Tarot features a number of tarot decks which incorporate magical plants and herbs. The lore of these ancient plants inspire and enrich these decks, and in turn our own appreciation of these green helpers grows.