For millennia, various plants have been billed as aphrodisiacs. These aren’t necessarily obscure species lurking deep in tropical jungles and known only to shamans. Wander over to the produce counter of any modern supermarket and reach for, say, a pomegranate, and you are cradling in your hand a fruit revered thousands of years ago by the Egyptians for its association with love and eroticism.

A number of spices, from lovage to nutmeg to vanilla, have been credited with the . . .