The Golden Fern ( Zlaté kapradí), Jiří Weiss, 1963

Wandering through the forest, a woodcutter finds a golden fern whose seed turns into a beautiful woman they fall in love. After getting drunk in a village feast, he gets to sign up to the army. The fairy gives him a shirt to wear and asks him to swear he will never abandon it. At the war front, he falls in love with the the colonels daughter and will have to perform various feats to get her attention.