On March 29 and 30, 1979, the Rijksherbarium at Leiden commemorated in a modest way its foundation by King William I, 150 years ago. On the first day of the celebration a large company, including several distinguished foreign botanists, gathered in the old central building of the University for a festive meeting during which a number of speakers dwelt upon past, present and future of the Rijksherbarium as well as on its role in botany.