A scientific meeting dedicated to the 100th anniversary of publishing one of Dr. Sava Petrović's main works «Niš Region Flora» was organized 25 years ago by a group of biologists from Doljevac, Leskovac, Prokuplje and Niš. At that time, nobody could presume that this type of botanist gathering from Serbia and surrounding countries would become one of the brightest traditions of Serbian botany at the end of previous and the beggining of this century.