Fulvifomes kawakamii is similar to F. imbricatus, but differs because it has much larger basidiocarps, larger pores (5–7 per mm), frequently branched generative hyphae and frequently septate skeletal hyphae in context, and slightly smaller basidiospores (4.5×3.5 μm). Fulvifomes grenadensis and F. nilgheriensis bear similarities to F. kawakamii too. However, fruiting bodies of F. grenadensis are solitary and develop a much darker crust on the surface of the pileus, are considerably smaller (12.5 x 9 x 5 cm), pores 4-7 per mm, with context hyphae up to 5 μm in diam, and with golden brown, somewhat thick-walled basidiospores that are mostly subglobose and 4-6 x 3-5 μm. Fruiting bodies of F. nilgheriensis are also solitary and much smaller (15 x 11 x 5 cm) than those of F. kawakamii, pores are 7-9 per mm, and basidiospores are subglobose, ferruginous brown, thick-walled, and 4-5.5 x 4-4.5 μm (Larsen et al. 1985, Zhou 2015, Jayawardena et al. 2019).

Although in GBIF there is only one record of the species, for the USA, the species is also recorded in Brazil. Furthermore, based on molecular analyses, some specimens identified as F. nilgheriensis of F. fastuosus may actually be F. kawakamii.

There are few reports for this species, with only one reported from USA. However, there are nine records from Brazil.

In Brazil it is reported for the Atlantic Forest and Amazonia.

The species in Brazil is present in pluvial forest domain. However, the Amazon has currently the highest rates of deforestation in the last decades and the Atlantic Forest is already a hotspot.

Some records in Brazil are in unprotected areas.

Other areas should be studied in order to assess the distribution of this species.

None.