Volhynian Polesia – main source of the Yellow Azalea (Rhododendron luteum Sweet) in European gardens and parks

Natural range of the Yellow Azalea Rhododendron luteum Sweet (Azalea pontica L.) includes the Caucasus, Asia Minor, Volhynia and SE rim of the Alps (Slovenia). There is also a natural locality of this species in Poland, in Wola Zarczycka near Le ajsk. The plant was discovered in 1795 in Volhynian Polesia by an eminent gardener Dionizy Mikler, and its popularity grew thanks to the Botanic Garden affiliated by the Krzemieniec College. Already at the first half of the 19th century Yellow Rhododendron, originating from Volhynian Polesia, was in cultivation in most of European Botanic Gardens. Nowadays this species can be easily found even in small private gardens. It has also been planted in forests. In Volhynian Polesia it grows abundantly in continental mesotrophic oak-pine mixed forests (Querco roboris-Pinetum), sometimes covering 100% of the shrub layer. Its is equally common in continental swamp pine forests (Vaccinio uliginosi-Pinetum). The soils where the species grow are always moist and very acidic (pH below 4). In Volhynia plant communities with R. luteum cover over 1.5 billion ha. In Ukraine the plant is not protected by law.