There is nothing to equal the Festival of the Fifth Month, when the scents of the iris and sagebrush mingle so charmingly. The children are proud of themselves and keep looking at the flowers on their sleeves, comparing them with those of their companions. This is all delightful, as are the little pages who play with the girls and snatch away their iris, making them burst into tears.
From the 10th century "Pillow Book of Sei Shonagon," translated by Ivan Morris (Penguin Books)
Evil spirits were abroad on the fifth day of the fifth month, but it was believed that iris and artemesia herbs gave protection. In the Imperial court, elegant decorations were made from the early-flowering Iris tectorum, but as the festival has evolved into Children's Day, we are much more likely to see hana shobu on display. Their lower petals are larger and upper standards are much shorter than the slender ayame type of iris. Also, their sword-shaped leaves are narrow and ridged. Traditionally, boys bathe with iris leaves on this day, as the plant symbolizes the warrior spirit. Incidentally, in England the wild water-loving iris also traditionally had mysterious powers and its name is "sweet flag," an ancient word for "sword."