By strict definition, a plant is a "natural" thing. It's organic if all its culture has been witthout synthesised chemicals.
Selective breeding is also natural. What about Natural Selection? Whilst a plant or animal species exhibits variation, selection can take place.
Many medicines began as plant extracts; Aspirin from the willow. Digitalis from foxgloves, morphine from poppies, quinine from the cinchona tree. atropine from deadly nightshade. the list is huge. the difficulty with using the plant directly is in measuring the dose. I think many medicines are still extracted from plants an processed to get a consistent dose. I've seen poppy fields around here and rather assumed they were medicinal rather than for culiunary purposes. I do mean the pinky white opium poppies, NOT the red cornfield ones.
Hana