Matronalia Festival

From Patheos:

Juno Capitolium was another goddess called upon by new brides and wives, for She is a goddess who protects the sanctity of marriage vows and marital relations.  A story grew up that Juno, already angry over her husband’s affairs, became even more infuriated when She learned that Jupiter had given birth to a daughter. To relieve Jupiter’s headache, Vulcan split open His head with a mallet and out arose wise Minerva. Grey-eyed Minerva was addressed as “most chaste goddess” because Her conception and birth had not resulted from sexual intercourse. Juno was so angered by this that She decided that She, too, would bear a child on Her own, without any help from Jupiter. She enlisted the help of Flora, Goddess of Flowers, who provided Juno with a sacred lily that held pollen-laced dew. This was the semen that Flora poured from the lily into Juno’s ear. This immaculate conception of Juno is celebrated on 2 May as another sort of Matronalia comparable to modern Mother’s Day. Then, on the first day of the New Year, the first day of March, Juno gave birth to Mars.