The main overall goal of the RJB's research is to understand the diversity of plants and fungi that exists, how this diversity has come about, and how it can be conserved.

The approaches taken to achieving this goal are very diverse, however. They range from studies aimed at finding out what species live in a particular territory (flora) or make up a particular group of organisms (systematics), to attempting to reconstruct the evolutionary history of groups of plants and fungi with a view to: (1) proposing a more natural classification based on this history; (2) contributing to reconstructing the tree of life; (3) determining how particular species have been distributed in space and time since their formation; and (4) providing a framework within which to infer what evolutionary changes have taken place within lineages, the mechanisms which have generated or modulated these changes, and their genetic basis.

The RJB's researchers also study biodiversity at the ecosystem level, particularly in the case of aquatic ecosystems in the Mediterranean region and the tropics.

We use a wide range of tools, methods and sources of information. The latter range from the most basic –based on a comparative study of the observable characteristics of specimens in the herbarium– through to the least accessible and closest to the genotype, such as molecular markers.