Krombholziella rugosa is a species described from the North of France. I has only been found between 1970 and 1975. This may be a rare species, but the lack of observations may also be due to confusions with other similar or potentially synonymous species. Taxonomic review and search efforts to determine current population size and distribution are needed. The species is assessed as Data Deficient (DD).

This is the only species in the genus Krombholziella, K. rugosa was assigned to this genus in a taxonomic review in 1985. All other species that previously belonged to this genus have since been transferred to other genera (Leccinellum and Leccinum). Synonyms: Leccinum rugosum and Boletus rugosus Fr. (1835) (nom. illegit., not to be confused with Boletus rugosus Jacq. (1774), synonym of Ganoderma lucidum). (Species Fungorum, 2023)

The species is only known from the north of France (Roost-Warendin and Carvin, Auchel and Lapugnoy in Pas-de-Calais).

Only known from 4 locations in the North of France, collected between 1970 and 1975 (Bon and Van Haluwyn,1981, GBIF.org 2023). The species has not been found since, and no more information is available. It may be rare since it is conspicuous and found in a region with generally high searching efforts. However it is also possible that it may be confused or a synonym of another species (e.g. Leccinum sp.) and forgotten to science. Therefore it is not possible to estimate current distribution, or population size and trends.

This is a terrestrial species, found in the presence of Betula, Salix and Calamagrostis epigejos (Bon and Van Haluwyn,1981).

Unknown.

Taxonomic review is needed to confirm the validity of this species and its placement in the Krombholziella genus. Targeted search efforts of known locations and other areas of suitable habitat are needed to establish its distribution range and current population size. and trends.