Hericium flagellum (Scop.) Pers. is considered a rare, wood-decaying fungus that occurs on coniferous trees, predominantly on silver fir (Abies alba). In this paper, a new locality of H. flagellum in Wielkopolska Voivodship is presented, along with the macro- and micromorphological features of the collected specimens. Basidiomata of H. flagellum were found in November 2016 and 2017 in the “Olbina” nature reserve (ATPOL Dc-97, Kalisz Forest District), located in a continental mixed coniferous forest close to the northern border of the natural range of silver fir. In 2016, H. flagellum was found growing in the hollow of an old stump of silver fir, and in the following year, this fungus was recorded on a fallen log of silver fir. The implications for conservation are briefly presented. Prospects of further development of the basidiomata of H. flagellum in the “Olbina” reserve are also discussed.