 547–48) he is the son of "grain-giving Earth", reared by Athena.The earth-born son was sired by Hephaestus, whose semen Athena wiped from her thigh with a fillet of wool cast to earth, by which Gaia was made pregnant.In the contest for patronage of Athens between Poseidon and Athena, the salt spring on the Acropolis where Poseidon's trident struck was known as the "sea of Erechtheus".