“Herbs gathered on May Eve have a mystical and strong virtue for curing disease; and powerful potions are made then by the skilful herb women and fairy doctors, which no sickness can resist, chiefly of the yarrow, called in Irish “the herb of seven needs” or cures, from its many and great virtues. Divination is also practiced to a great extent by means of the yarrow. The girls dance round it singing… “Yarrow yarrow yarrow, I bid thee good morrow, and tell me before to-morrow who my true love shall be.”

Lady Wilde, Ancient Legends, Mystic Charms & Superstitions of Ireland: with sketches of the Irish past, 1919