While mistletoe sounds more like a foot condition than anything that would
inspire romance, you should probably count your blessings that all you're
getting is a kiss. Once upon a time, it was more customary to sacrifice a bull
or ox under the mistletoe.
Mistletoe is an interesting plant. It's a parasite; in fact it's the only plant
that is actually considered a true parasite because it sometimes kills the
hardwood trees it infests. Mistletoe grows slowly in trees, and doesn't put
roots in the ground.
This liberation from the earth made the ancient Druids believe mistletoe was
sacred. It was even considered bad luck to let any mistletoe touch the ground.
The Druids believed mistletoe could provide protection; promote fertility, love,
and health; and exorcise demons. Putting it in a baby's crib would keep the
fairies from whisking away your child. And some people even believed that
wearing it around your neck could make you invisible. (But maybe only in the way
that drinking a lot of mead could make you really good-looking.)
The tradition of kissing under the mistletoe probably got its start with the
Druids as well.
According to one explanation, the Norse god Balder was killed with an arrow made
of mistletoe. The rest of the gods were sad, so they decided to bring him back
to life. The Goddess of Love then dedicated the mistletoe to Balder--and anyone
passing under it must receive a kiss to show tribute to this symbol of love.
Others point to the Druid tradition of laying down arms and exchanging greetings
under the mistletoe as the origin of the kissing tradition. They credit the
English for taking peace one step further by puckering up, then plucking a berry
from the bunch and discarding it. The kissing ended when the berries ran out,
inspiring people to find hearty bunches.