EN
The article presents Joseph Decaisneʼs Polish correspondents in light of documents preserved at French Institute and National Natural History Museum in Paris. Decaisneʼs correspondence with Willibald Besser and Antoni Andrzejowski, of the Lyceum of Krzemieniec, is discussed. It is important for the history of the Krzemieniec Botanical Garden, and for learning about Ukrainian flora. The letters of Ignacy Rafał Czerwiakowski, Edward Janczewski and Antoni Rehmann contain much information about the work of the Krakowian botanists together with the Jardin des Plantes, but also valuable information about the history of Darwinism in Poland, and the acclimatisation of fruit trees in Poland. Edward Strasburgerʼs correspondence is an interesting contribution in learning about the early years of emigration of the academic. There are also a few letters sent to Decasisne by senders who were not naturalists, but contacting him with various requests.