Exsiccati are a series of published, uniform, numbered sets of preserved specimens collected in duplicate by an expert and distributed among other herbaria. For over two centuries, exsiccati have been issued in sets of ten to a hundred often based on thematic subjects within botany or mycology. In the past, the sale of exsiccati series was an important source of income for several renowned collectors. In addition, the exsiccati exchange has historically been an important way for botanical institutions to share information about their regional floras.

The exsiccati feature needs to be activated within the central configuration file before it is available within a Symbiota portal. Before activation, it is recommended that exsiccati title table (omexsiccatititles) is pre-loaded. Once a title has been added to the index, data entry personnel can add a new number and link specimens to a title within the occurrence data entry form. Once a number of exsiccati titles have been linked to a number of specimens, a link to the index page (/collections/exsiccati/index.php) can be added to the left menu of the portal.