Fomitopsis roseoalba Soares, Ryvarden & Gibertoni

MycoBank number: MB 812876 Facesoffungi number: FoF 2959

Etymology: The name refers to the colour of basidiomata when fresh, with pore surface white, and upper surface, when present, pink to lilac.

Holotype: URM 86923

Basidiomata annual, pileate, resupinate to effused-reflexed. When resupinate, up to 32 cm long, 11 cm wide, 0.3 cm thick at centre. Pileus when present, 0.2–7 cm wide, 5 cm long, 0.3 cm thick at base, upper surface white to pink (3.1A white, 7.4B pink) when fresh, becoming cream to greyish when dried (3.3A pale yellow, 1.1C pastel grey), slightly velutinate. Context white to cream (3.1A white, 3.3A pale yellow), 0.4 cm thick. Margin narrow in resupinate specimens, obtuse in pileate specimens. Pore surface white to cream (3.1A white, 3.3A pale yellow) when fresh and ochraceous when dried (4.4A light yellow), pores circular to angular (4–6 mm), dissepiment thin and entire.

Basidiospores ellipsoid to sub-cylindrical, 3–4 × 1.8–2 μm, smooth, thin-walled, IKI. Hyphal system trimitic, generative hyphae clamped, thin-walled, 2.5–3 μm in diam.; skeletal hyphae dominant, thick-walled, hyaline, 3.75–5 μm in diam.; binding hyphae thick-walled, hyaline, 1.5–2 μm in diam. Cystidia absent. Basidia clavate with four sterigmata, 10–12 × 5–7 μm.

Material examined: BRAZIL, Amapá: Porto Grande, Floresta Nacional do Amapá, on dead hardwood, 00 58. 25.8 N and 051 41 73.6 W, February 2014, A. Soares, AS 1496 (URM 86923, holotype, Isotype O); Porto Grande, Floresta Nacional do Amapá, on dead hardwood, September 2013, A. Soares (URM 86913), A. Soares (URM 86926); February 2014, A. Soares (URM 86918), A. Soares, AS 1431 (URM 86920) A. Soares, AS 1457 (URM 86921), A. Soares, AS 1566 (URM 86922), A. Soares (URM 86923), A. Soares (URM 86925); Brazil, Pará: Melgaço, Floresta Nacional de Caxiuanã, July 2006, T.B. Gibertoni (URM 79982, 79984, 79985, 79986, 79987, 79988, 79989, 79990), March 2007, T.B. Gibertoni (URM 79983, 79991, 79993, 79994, 79995, 79996), August 2007, T.B. Gibertoni (URM 79997, 79998, 79999, 80000, 80001, 80002, 80003, 80004), February 2008, T.B. Gibertoni (URM 79992, 80005, 80006, 80007, 80008), August 2013, A. Soares (URM 86912) A. Soares (URM 86914) A. Soares (URM 86915), A. Soares (URM 86916). GenBank numbers ITS:KT189139; LSU:KT189141.

Notes: This species is easily recognized by the white to pink, pileate to effuse-reflexed basidiomata. Of the neotropical species, F. nivosa (Berk.) Gilbertson and Ryvarden has similar whitish colour and morphology (pileate, and sometimes effused-reflexed), but is separated by having cylindrical basidiospores (6–9 × 2–3 μm) and smaller pores (6–8 mm). Despite herbaria revision and several collections in other parts of the Brazilian Amazonia, F. roseoalba was only found in the Eastern Brazilian Amazonia, what indicates that this species may be restricted to this region. According to our molecular analyses, F. roseoalba grouped into a well-supported clade (81/0.99) with one unidentified, endophytic Fomitopsis isolated from Hevea brasiliensis sapwood collected in Brazil (Fomitopsis sp. NHB31) (Martin et al. 2015). This isolate may represent an endophytic stage of F. roseoalba. The F. roseoalba clade grouped in a major clade (98/1.00) with F. subtropica B.K. Cui, Hai J. Li and M.L. Han and two unidentified, endophytic Fomitopsis isolated from Elaeis guineensis from Thailand (Fomitopsis sp. 9V 3.1 and Fomitopsis sp. 7R 8.1) (Rungjindamai et al. 2008), all included in the Fomitopsis sensu stricto (75/1.00).When in a resupinate form, F. roseoalba is whitish as F. subtropica, and both have similar basidiospores (cylindrical to oblong-ellipsoid 3–4.7 × 1.7–2.3 μm in F. subtropica). Fomitopsis subtropica, however, has smaller pores (6–9 mm) and the pileus, when present, is white to cream (Li et al. 2013b). Li et al. (2013b) suggested that the two specimens of Fomitopsis sp. from Thailand (7R 8.1, 9V 3.1) could be F. subtropica, because of the high supporting values uniting them in their study (100/1.00). Although the phylogenetic relationship of these three Fomitopsis species was strongly supported, our analyses indicates that F. subtropica, F. roseoalba and Fomitopsis sp. (7R 8.1, 9V 3.1) are clustered in an independent way.

Maximum likelihood phylogenetic tree of the concatenated ITS1, 5.8S, ITS2 and partial 28S rDNA sequences. Bootstrap supporting values (1,000 replicates) and posterior probabilities (PP) from Bayesian analysis to each node are shown from left to right. Only bootstrap values above 50% and PP above 0.75 are provided. The new species described in this study are highlighted in blue. The tree was rooted with Grifola sordulenta and Perenniporia ochroleuca.


Fomitopsis roseoalba (URM 86923, holotype). a, b Fresh basidiomata. c Dried basidiomata. d Basidia. e Basidiospores. f Context. Scale bars: a-c = 1 cm, d, e = 2 m, f = 10 m (photos by T.B. Gibertoni).