'Chrysanthemum day'. The last of the five gosekku days. The main activity is a party for chrysanthemum-viewing, sometimes in the grounds of a shrine. The growing of chrysanthemums of all shapes and sizes and modelling of shapes in chrysanthemums was a highly-developed art-form in Japan, from where it was introduced to Europe in the mid-nineteenth century, but the imperial symbolism associated with chrysenthemum culture apparently dates from the Meiji period. The sixteen-petalled chrysanthemum, a motif apparently deriving from an older imperial banner showing the sun with rays became the symbol of the emperor Meiji. The order of the chrysanthemum, the highest order of knighthood in a new European-style honours system was inaugurated in 1875.
A Popular Dictionary of Shinto. Brian Bocking.