On Food and Cooking

play in the lives of the plants themselves?
One simple clue is their very potency. Try
the experiment of chewing on an oregano leaf,
or a clove, or a vanilla bean. The result is far
from pleasurable! When eaten as is, most
spices and herbs are acrid, irritating, numbing.
And the chemicals responsible for these
sensations are actually toxic. The purified
essence of oregano and of thyme can be
bought from chemical supply companies, and
come with bright warning labels: these
chemicals damage skin and lungs, so don’t
touch or inhale. This is precisely the primary
function of these chemicals: to make the
plants that produce them obnoxious and
therefore resistant to attack by animals or
microbes. The flavors of herbs and spices are
defensive chemical weapons that are released
from plant cells when the plant is chewed on.
Their volatility gives them the advantage of
counterattacking through the air, not just on
direct contact, and of being a warning signal