Josef Armin Knapp (1843-1899) as Austrian botanist was interested in development of botanical knowledge of Austro-Hungarian Monarchy - his maternal country. Monarchy, during the long regency of emperor Franz Josef I, was multinational, very much diversified geographically territory. This large empire had included, among others, such countries as present Austria, Hungary, Slovakia, Croatia, Ukraine, Romania and the southern part of present Poland - previously known as Galicia. J. A. Knapp was interested in studying these parts of empire which were considered peripheries and less-known. It seems to have met the requirements of science, economy and administration of Vienna. J. A. Knapp in his large floristic researches had included explorations of considerable part of the Monarchy and had left an interesting scientific legacy. His research papers were results of botanical explorations in selected areas of the Monarchy - area of Nitra (currently a city in Slovakia), Slavonia (presently a land in Croatia) and Galicia (the historical area in the south of Poland). This article refers to the botanical journey of J. A. Knapp in Galicia in summer 1868. The main purpose of his journey was to visit and explore selected places in Galicia - the surroundings of Jaslo and Sanok towns and some specific areas within the Bieszczady Mountains, which are part of the Carpathians Mountains. Botanical researches in the Bieszczady Mountains provided by J. A. Knapp can be considered nowadays as very important and pioneering in that area. In the second part of XIX century this area was highly populated and the observed anthropogenic pressure applied to the nature was strong. Now, the area is considered a very valuable natural territory - since 1973 it has been occupied by the Bieszczady National Park - one of Polish national parks. J. A. Knapp had spent more than two months in Galicia thanks to the great hospitality of Polish people, especially botanists: A. Rehmann, I. R. Czerwiakowski, W. Jablonski. Floristic data from Galicia were popularized by J. A. Knapp in a research paper Przyczynek do flory obwodów jasielskiego i sanockiego (Flora of Jaslo and Sanok area) translated from German to Polish by W. Jablonski and published in well known scientific magazine Sprawozdania Komisji Fizjograficznej (Reports of Physiographic Commission),edited in Cracow in 1869. The great part of this paper was occupied by a large floristic list, which included 800 species of vascular plants collected in Galicia by the author himself or sometimes by other botanists. The results of J. A. Knapp's studies were also published in his book Die bisher bekannten Pflanzen Galiziens und der Bukowina, edited in Vienna 3 years later. In the publication in question the author proved to have possessed a profound knowledge of the flora of Galicia and Bukovina (now it's a region in Romania and Ukraine), thanks to the experience based on his own results obtained during the journey to Galicia, and based on others botanical data collected in the scientific literature by various botanists. Studies made by J. A. Knapp in Jaslo and Sanok towns and in the Bieszczady Mountains and his complete lists of plants collected in areas of Galicia and Bukovina could be very useful for contemporary botanists and ecologists as the basis for comparisons and evaluation of the flora changes in the natural environment over centuries.