Delimitation of taxa in Amauroderma (Ganodermataceae, Polyporales) based in morphology and molecular phylogeny of Brazilian specimens Author Gomes-Silva, Allyne C. Universidade Federal de Pernambuco, Centro de Ciências Biológicas, Departamento de Micologia, Av. da Engenharia s / nº, CEP 50740 - 600, Recife, Pernambuco, Brazil. Author De Lima-Júnior, Nelson C. Universidade Federal de Pernambuco, Centro de Ciências Biológicas, Departamento de Micologia, Av. da Engenharia s / nº, CEP 50740 - 600, Recife, Pernambuco, Brazil. Author Malosso, Elaine Universidade Federal de Pernambuco, Centro de Ciências Biológicas, Departamento de Micologia, Av. da Engenharia s / nº, CEP 50740 - 600, Recife, Pernambuco, Brazil. Author Ryvarden, Leif University of Oslo, Department of Biosciences, P. O. Box 1066, Blindern, N- 0316, Oslo, Norway. Author Gibertoni, Tatiana B. Universidade Federal de Pernambuco, Centro de Ciências Biológicas, Departamento de Micologia, Av. da Engenharia s / nº, CEP 50740 - 600, Recife, Pernambuco, Brazil. text Phytotaxa 2015 2015-09-25 227 3 201 228 http://dx.doi.org/10.11646/phytotaxa.227.3.1 journal article 10.11646/phytotaxa.227.3.1 1179-3163 13632811 Amauroderma subsessile Gomes-Silva, Ryvarden & Gibertoni , sp. nov. , Fig. 12 MycoBank: MB 811032 Amauroderma subsessile is characterised by the short to long, laterally stipitate basidiomata and homogeneous context. Holotype :— BRAZIL . Rondônia : Porto Velho , Parque Natural Municipal de Porto Velho , in dead wood, February 2011 , A.C. Gomes-Silva 2975 ( URM 83239 ). Etymology: —sub (Latin) = somewhat, sessilis (Latin) = sessile , referring to the basidiomata not completely sessile, with a short to long stipe. Basidiomata annual, solitary to clustered, lateraly stipitate. Pileus single to clustered, semi-circular, applanate, 2–5 cm wide, 2.5–4 cm long, 0.1–0.2 mm thick, hard when dry. Stipe usually split, cylindrical, lateral, solid, 2–5 cm long, 0.2–0.4 mm diam., dark red (Bay 19), dull, glabrous, with thin cuticle, context with two black lines, fibrous, white to cream (B 2, C 3). Abhymenial surface dull, glabrous, concentrically zonate, slightly radially sulcate when dry, dark red (Bay 19) close to the stipe, orange (Sienna 11) to brown (Fulvous 12) in the intermediate part and gray (Smoke grey 34) close to the margin. Margin entire, acute, slightly involute when dry, concolorous to the hymenial surface. Hymenial surface cream (B 2) to brown (Snuff brown 17), poroid, pores circular, 6–7 per mm, dissepiment entire, thin. Context with two black lines, fibrous, 0.1–0.2 mm thick, white (B 2) to cream (B 2). Tubes concolorous to the hymenial surface, shallow. Hyphal system dimitic; generative hyphae hyaline, clamped, thin-walled, 2–3.5 μm diam.; skeletal hyphae hyaline to yellowish, thick-walled to solid, arboriform, 3.5–4.5 μm diam., IKI-. Hyphal pegs absent. Basidia not observed. Basidiospores globose, yellowish in KOH, distinctly ornamented, guttulate, 8–10 μm, IKI- to rarely slightly IKI+. Substrate: —in dead hardwoods. Distribution: —in the States of Pará and Rondônia in the Brazilian Amazonia, and Costa Rica and Panama . Specimens examined: — BRAZIL . Pará : Melgaço, Estação Científica Ferreira Penna, March 2007 , T.B. Gibertoni 15 (URM 80018, on Fabaceae ), T.B. Gibertoni 161 (URM 80015, on Eschweilera sp. ); February 2008 , T.B. Gibertoni et al. 5, 184, 265 (URM 83248, URM 80017, on Fabaceae, URM 80016). Rondônia : Porto Velho, Estação Ecológica de Cuniã, March 2012 , A.C. Gomes-Silva & T.B. Gibertoni 46 (URM 83241); Parque Natural Municipal de Porto Velho, August 2011 , A.C. Gomes-Silva 3062 (URM 83584). COSTA RICA . Balboa, on bole of tachi, 1975, R. Foster w/n (O 13227). PANAMA . Gatun Lake, Barro Colorado Island, March 1982 , L. Ryvarden 1999 (O 13318). Remarks: — Amauroderma subsessile can be distinguished by the short to long, laterally stipitate basidiomata, brown, and zoned abhymenial surface. So far, it is the only stipitate species of Amauroderma known to grow exclusively on dead hardwood. FIGURE 12. Amauroderma subsessile (URM 83239). A. Abhymenial surface. B. Hymenial surface. C. Basidiospores in Melzer’s reagent. D. Basidiospores in SEM. Scale: A–B = 1 cm; C–E = 10 μm. Photos: A.C. Gomes-Silva. Amauroderma trichodermatum J.S. Furtado, Revisâo do gênero Amauroderma (Polyporaceae) ; Estudos baseados nas microestruturas do basidiocarpo: 311 (1968) Description:— Furtado (1981) , Ryvarden (2004a) , Robledo et al. (2015) . Substrate: —on dead wood and on soil. Distribution: — Bolivia , Brazil , Guyana and Venezuela . Specimens examined: — BRAZIL . Amazonas, Rio Cuieiras-Manaus trail, Km 1, April 1974 , D.G. Campbell P21898 (INPA 45838). Remarks: — Amauroderma trichodermatum is characterised by the zonate abhymenial surface with tomentose and glabrous zones.