Plant collections in herbaria are potentially valuable seed sources for conservation and recovery. This paper explores the feasibility of "resurrecting" 26 extinct taxa from the Belgian flora by analysing the viability of seeds from old herbarium specimens that had been stored for 23 to 158 years. Seed viability was estimated by performing germination tests according to standard procedures. Germination was achieved for eight seeds from three herbarium specimens of a single species, Bupleurum tenuissimum, aged 101, 125 and 144 years. Seed maturity, storage conditions and seed senescence were the main factors influencing the viability of the investigated seeds.