Seven Dhatus

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.

Creation is light

Plants give us the love, the nourishing power of the sun, which is the same energy of all the stars, of all light. These cosmic energies emanated by plants thus nourish, sustain and make grow our own astral body. In this way the existence of plants is a great offering, a sacrifice. They offer us not only their own nutritive value, but the very light and love from the stars, from the cosmos whose messengers they are. They bring to us the universal light so that we can enter the universal life. They exist for psycological, as well physical nourishment.
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Plants exist to transmute light into life. Human being exist to transmute life into consciousness, love. [...] Plants exist to transmute light into life trough photosynthesis. the human being transmutes life into consciousness through perception.
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The proper usage of a plant or herb, during which its true power is released, implies a communion with it. The plant, when we are one with it, will vitalize our nervous system and invigorate our perception. This means giving value to a plant as something sacred, as a means of communion with all nature.

From "The Yoga of Herbs" David Frawley and Vasant Lad.