The Rijksherbarium and its contribution to phycology

In modern handbooks the development of plant systematica is given as occurring in four overlapping phases: the pioneer (or exploratory) phase, the consolidation phase, the biosystematic phase, and the encyclopaedic phase. In systematic phycology research is still largely in the pioneer phase, with scattered attempts to reach the second, third, or even fourth phase. In many cases in phycology the biosystematic phase has to precede the consolidation phase. Knowledge of algae (growing mainly in marine or freshwater environments, but also occurring in soils or snow and on rocks or trees) is quite scanty in most parts of the world, and even for taxa that are supposed to be well known, the information is often but fragmentary. The encyclopaedic phase is for most groups of algae very remote and probably it will never be attained. Research on algae connected with the Rijksherbarium reflects the phases of systematic phycology.