In Ancient Ukrainian mythology, the oak and its leaves symbolize Perun, the god of lightning; to honor him, the Slavs burned fires of oak logs and branches.  The oak carries his attributes: strength and power.

Oak leaves are distinct, and were shown on pysanky with wavy contours, sometimes interspersed with acorns. These an examples of the oak leaf motif from Zaporizhia and Pokuttia:

     

These are examples of pysanky with oak leaf motifs from Sokal; the one on the right also has acorns.  Pysanky from Sokal often have botanical themes, and tend to be more naturalistic than those from other regions.

     

     

These are pysanky with oak motifs from Vinnytsia (Podillia).  These oak leaves are much more stylized

     

     

And here are a few examples from the Kyiv area (Podniprovia):

     

     

This example is from southern Ukraine, Kirovohrad oblast (Prymoria). 

It is quite similar to the one from Zaporizhia; the two areas are ethnographically similar.