Riding Icarus: More about Ukrainian folklore:

 

Riding Icarus borrows a great deal from Ukrainian myth and folklore. There are still ‘wise women’ and men in Ukrainian villages who practice many of the traditions in the book, like pouring wax into water to explain and cure nightmares. I took other motifs from folk and fairy tales, in particular a series of stories by the writer Nikolai Gogol called Village Evenings Near Dikanka. They are funny, frightening, magical and humdrum all at once, describing Ukrainian village life nearly two centuries ago as well as many legends and traditional celebrations like the midsummer festival of Ivana Kupala.

  Ivana Kupala is the Slavic version of the ancient midsummer festival celebrated all over the northern hemisphere. Originally a pagan celebration (where the word Kupala comes from) it was later combined with the Christian feast of St John the Baptist (Ivan). On the night of Ivana Kupala people lit bonfires and would jump through the flames; if a couple managed to hold hands as they jumped it meant they would stay together for a long time. Girls floated candles and flower wreaths on the river to foretell who they would marry. Midnight on the eve of Ivana Kupala was the only time the fern flower bloomed. It was said to grant wishes and bring riches but only if the seeker could withstand the forces of evil.

  One of the most famous retellings of the fern flower legend is ‘The Eve of Ivana Kupala’ by Nikolai Gogol, which is retold in chapter 15 of Riding Icarus. Gogol’s story has a tragic ending because the hero, Petro, though he finds the fern flower, isn’t strong enough to resist the devil (here called Basavryuk) and the witch Baba Yaga, and he does something terrible….  

People still celebrate Ivana Kupala in Ukraine and other Slavic countries. I’ve never heard of anyone really finding the fern flower though.