A wealth of information comes our way via Mexico Bob. Apparently the citron has quite a pedigree. In the ancient world it was employed both as an emetic and as a mouthwash. Here’s this from Theophrastus:
In the east and south there are special plants… i.e. in Media and Persia there are many types of fruit, between them there is a fruit called Median or Persian Apple. The tree has a leaf similar to and almost identical with that of the andrachn (Arbutus andrachne L.), but has thorns like those of the apios (the wild pear, Pyrus amygdaliformis Vill.) or the oxyacanthos (the fire thorn, Cotoneaster pyracantha Spach.), except that they are white, smooth, sharp and strong.
The fruit is not eaten, but is very fragrant, as is also the leaf of the tree; and the fruit is put among clothes, it keeps them from being moth-eaten. It is also useful when one has drunk deadly poison, for when it is administered in wine; it upsets the stomach and brings up the poison. It is also useful to improve the breath, for if one boils the inner part of the fruit in a dish or squeezes it into the mouth in some other medium, it makes the breath more pleasant.
And this from Pliny the Elder:
The Assyrian fruit, which some call Median, is an antidote for poisons. Its leaf is like that of the andrachn (Arbutus andrachne L.), but with thorns running between. The fruit is notable for the fact that it is not eaten and has a strong odor, as also do the leaves, which impregnates clothes stored with them and keeps away harmful insects.
This is the fruit whose pips we have related Parthian nobles boiled in foods in order to eliminate bad breath. No other tree is so highly praised in Media.
And that’s still not all:
The citron is also used by Jews for a religious ritual during the Feast of Tabernacles, by whom it is called Etrog. Therefore the citron was always considered as a Jewish symbol, and is found on various Hebrew antiques and archeological findings.
Whew! Thanks Bob! Everything I ever wanted to know about the citron in one easy blog post.