The botanical section of the Calderini Museum is mostly represented by the collections of the Valsesian botanist Antonio Carestia (1825-1908), one of the greatest scholars of Valsesian flora as well as an internationally recognized botanist. Abbot Carestia delivered part of the herbarium he created in May 1870, continuing in the following years to increase the collection of phanerogams he had set up with further specimens, also adding collections of cryptogams, algae and lichens.

The recent cataloging and digitization of the folders and herbarium sheets that make up the work of the Valsesian abbot, accompanied by a critical review of the specimens, led to a better clarification of the original determinations and a quantification of the museum samples: the herbarium of property of the naturalistic institution is thus composed of 1050 sheets and packages, with 1427 species represented and for a total of 1995 specimens.