Twenty-three specimens of fungi of genus Fomitiporia Murrill, collected in the Amazonian region in the states of Amazonas and Roraima in their respective rainy periods were analyzed. The present study has both resulted in the description of eight species, namely F. apiahyna s. l. (Speg.) Robledo, Decock & Rajchenb., F. calkinsii (Murrill) Vlasák & Kout, F. conyana Alves-Silva & Drechsler-Santos, F. impercepta Morera, Robledo&Urcelay, F. langloisii Murrill, F. maxonii Murrill, F. murrillii Alves-Silva, R.M. Silveira & Drechsler-Santos and F. neotropica Camp.-Sant., Amalfi, R.M. Silveira, Robledo & Decock contributed with new records for the Amazonian region, Brazil and the Americas.

Fomitiporia specimens were collected from 2016 to 2017, in the states of Amazonas [Adolph Ducke Forest Reserve and Tropical Silviculture Experimental Station (ZF-2)] and Roraima (Maracá Ecological Station and Viruá Nacional Park) (Fig. 1). Specimens were photographed in scale, and, then, removed by hand or with the aid of a pocket knife (Fidalgo and Bononi 1989). They were packed separately in paper bags, and data related to site, date, collector, habitat and basidiomata (shape, consistency, mode of insertion in the substrate, coloring and dimensions), were recorded (Robledo and Urcelay 2009). The material was dried at a temperature close to 40^o C, for 48–72 hours. Subsequently, all fungal exsiccates were deposited at the INPA Herbarium.

Notes were taken regarding the basidiomata length, width and thickness, as well as hymenophore characteristics, pileus surface, pores and tube layers number and basidiomata consistency, in order to carry out the macroscopic analyses. Measurements were made with a ruler and/or caliper and the coloring was determined with the aid of Kueppers (1982).

Microscopic structures: hyphal system, basidiospores, sterile elements (setae, cystidia) were characterized and measured, under a micrometer-eyepiece (Teixeira 1995). Melzer’s reagent (IKI) was used to check the dextrinoid or amyloid reaction of basidiospores and/or hyphae, 3% aqueous KOH (Potassium Hidroxide) solution which hydrates structures and determines xanthochroic and Cotton Blue reaction, to ascertain the cyanophilic reaction (Teixeira 1995). Microstructure illustrations were made from photos taken with a microscope-coupled camera (LEICA DM500).