Doctrine of Signatures

The idea that a plant contains within it some sign or 'signature' from God that gives a clue to it's potential use [105]. Such beliefs have been popular at some point in most cultures around the world and are still apparent today.

Examples:Yellow plants for jaundice.

Red plants for blood.

Fruits shaped like genital organs to promote fertility [105].

Specific Plants:

Lungwort (Pulmonaria officinalis) with white blotches on the leaves resembling alveoli or possibly mucus build-up in lungs has a traditional use as an expectorant.

Other Reference: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith