The lichen collection "Abramo Massalongo" includes 594 exsiccata of 490 taxa, mainly collected in North-Eastern Italy between 1845 and 1855. The specimens were collected for the most part by Massalongo himself, and to a minor extent to other authors. Some specimens from Cadore were collected by Adolf von Berenger, some from the area of Verona by Carlo Tonini, while those of foreign origin by Elias Magnus Fries (Lapland), Georg Ernst Ludwig Hampe, Ernst Heinrich Friedrich Meyer and Friedrich Welwitsch (Central Europe), Gustav Wilhelm Körber (Sweden), Sébastien Lenormand (France), and Wilhelm Siegmund (Germany). Twenty-six specimens have no indication of the locality of provenance. Two of them come from the herbaria of Giuseppe De Notaris and Santo Garovaglio.

The collection was donated in at least two batches by Massalongo - a few years before his death - to the Istituto Veneto di Scienze, Lettere ed Arti; from here it was accessed at the Museum of Natural History in 1923 as a permanent deposit along with other scientific collections of the Istituto.

The collection consists of four issues containing 231 loose herbarium sheets and was probably arranged by Michelangelo Minio, director of the Museum from 1923 to 1947 [fig. 2]. The specimens are ordered alphabetically by genus and separated by substrate. Two issues contain lichens collected “on bark and soil,” while the other volumes contain lichens collected “on rock and bricks.” Each sheet hosts one to many specimens, either placed in envelopes or glued on a cardboard, sometimes folded for preservation purposes.

All specimens are identified at least at the species level. The taxon name is always handwritten near the specimens, together with information such as the locality of collection, while the year of collection is present for a minority of specimens only. Information on synonyms, bibliographic references, substrate type, abundance, and reproductive stage can be reported. If the collector was not Massalongo, the name of the correspondent who sent the specimen, the herbarium of origin, and the collector are reported as well.