The plant, like the human being, and the universe itself, is similarly composed of seven Dhatus or seven plane. The juice of the plant is the plasma. The resin of the plant is its blood. The softwood is muscle. The gum is its fat. The bark is its bones. The leaves are its marrow and nerve-tissue. The flowering tree shows these tissues in their most developed state. The tree is to the plant world what the human being is to the animal kingdom. [...]
Plants similarly posses their own Ojas (the energy and love within their system). But, they can transmit Ojas when used with love. Remedies producted with love, even when not "therapeutically" sound, may work wonders. Love is the true healing force; herbs and other means are merely vehicles.
From "The Yoga of Herbs" David Frawley and Vasant Lad.