The Medicine Buddha is prominent in most forms of Buddhism.
He is pictured holding Haritaki, also known as the Myrobalan plant.
In Tibetan Buddhism, Haritaki, also known as Myrobalan, is regarded as the only herb capable of healing illnesses that have their root cause in conflicting emotions.
"Ancient teachings tell us that merely seeing the Medicine Buddha, or even seeing an image of the Medicine Buddha, or hearing the name of the Medicine Buddha, can confer inconceivable benefits.
In Tibetan images of the Medicine Buddha, the left hand typically holds a blooming myrobalan plant. Tibetan medicine recognizes three basic types of illness, the root causes of which are the conflicting emotions -- passion, aggression, and ignorance. Myrobalan is the only herb in the Tibetan pharmacopoeia that can aid in healing each of these three types of diseases. This is like the action of the Buddha of Healing, who has the power to see the true cause of any affliction, whether spiritual, physical or psychological, and who does whatever is necessary to alleviate it."
This quote above is from this web site: http://www.dharma-haven.org/tibetan/medicine-buddha.htm
In Tibetan Buddhism, the power of the mind in healing is stressed The deity is sometimes depicted holding myrobalan fruit called dug-bcom, which means "that which renders poison inactive" (Dummer, p.26). Dug-bcom is a Tibetan healing symbol and a metaphor for the Three Poisons: desire, hatred and confusion. See source here
Haritaki is considered in Tibetan Buddhism to be for more than the body. To quote Dr.Natalia Bolsokhoyeva, who writes in Buddhist Himalaya VOL. V NO. I & II 1993:
Myrobalan (Tib: A-ru-ra) affects the mind as well as the body. It underlines the nature of the Buddha of Healing. In the Tibetan medicine, Myrobalan is considered as the universal treatment, which may cure all 404 diseases (2), known in the Tibetan clinical medicine. Source: http://buddhism.lib.ntu.edu.tw/FULLTEXT/JR-BH/bh117520.htm
To realize the importance of Haritaki to the Medicine Buddha, look at what he said he was here to do.
Quote from the Medicine Buddha Sutra:
"Therefore the World's Most Venerable entered into a Samadhi called the Removal of Suffering for All Beings. While He was in this contemplation a great radiance of light was sent forth from his Ushnisa, and he pronounced the great Dharani as follows:
NAMO BHAGAVATE BHAISAJAYA-GURU-VAIDURYA-PRABHA-RAJAYA TATHAGATAYA ARHATE SAMYAKSAMBUDDHAYA TADYATHA
OM BHAISAJYE BHAISAJYE BHAISAJYA SAMUDGATE SVAHA
When He, in his radiance, had spoken this mystical formula, the earth was shaken and emitted a great light. All beings were delivered from their diseases and miseries, they are now happy because their bodies and minds are at rest. "
Again we come back to the Mind as the center of cure for all illness, which in fact leads to enlightenment, mystical powers and a remarkable life. I find it so interesting that sitting right under our noses is clear evidence of the power of Haritaki to advance our consciousness, yet that aspect of its use has not been focused on in more recent times.
This video explains about the Medicine Buddha and Haritaki