Kitaibelia vitifolia, Russian Hibiscus
In 1967 Hungary issued a seven-stamp series to commemorate the 150th Anniversary of the Death of Pal Kitaibel, 3rd February 1757- 13th December 1817
I haven't been able to find an article mentioning this Russian hibiscus, Russian ivy, Russian sage and Russian vine but no Russian hibiscus. However, all is not lost, there are seeds on offer from France and the USA in the seed list