The seed of a pine tree, found within pinecones, is called a pine nut, or pignoli (in more proper Italian, pinoli). It’s easily found in grocery stores, either on their own or as part of pesto. Of the many species of pine, maybe 20 have seeds large enough to bother harvesting. Each has a slightly different taste, but in general they are delicately flavored and pleasantly textured.
In the second century A.D., the Greek doctor Galen prescribed pine nuts to his patients who had problems producing children. It’s unclear whether the goal was better fertility or an increase in the number of attempts, but his recommendation has survived for nearly two millenia and is echoed by cultures worldwide. Current thinking leans toward their increasing the libido, but I’ve yet to find any reliable evidence to corroborate it. Like many nuts, their high zinc content is useful for male potency. It’s a start, but that’s about it.
Rare and hard to find foods have often been considered arousing, giving some a boost in reputation only where they are foreign. This labor-intensive item may have received its notoriety from a slightly different combination, that of a lush and fatty flavor being found in a fairly hard to obtain (and tiny) form.