Amauroderma sessile Gomes-Silva, Ryvarden & Gibertoni, 2015

Gomes-Silva, Allyne C., De Lima-Júnior, Nelson C., Malosso, Elaine, Ryvarden, Leif & Gibertoni, Tatiana B., 2015, Delimitation of taxa in Amauroderma (Ganodermataceae, Polyporales) based in morphology and molecular phylogeny of Brazilian specimens, Phytotaxa 227 (3), pp. 201-228 : 220

Amauroderma sessile Gomes-Silva, Ryvarden & Gibertoni , sp. nov., Fig. 11

MycoBank: MB 811031

Amauroderma sessile is characterised by the lack of stipe and the flabelliform pileus.

Holotype:— BRAZIL. Pará: Oriximinã , dead wood, February 1980, V. L. Bononi ( INPA 103576 ).

Etymology: —sessilis (Latin) = sessile , referring to the basidiomata without stipe.

Basidiomata annual, solitary, sessile. Pileus single, semi-circular to flabelliform, applanate, 4–6 cm wide, 3–5.5 cm long, 0.1–0.2 mm thick, hard when dry. Abhymenial surface dull, glabrous, azonate, radially sulcate when dry, black at the base (Fuscous black 32), brown (Cigar brown 16, Snuff brown 17). Margin entire, acute, slightly wavy, involute when dry, concolorous to the abhymenial surface. Hymenial surface brown (Snuff brown 17), poroid, pores angular, 5–6 (7–) per mm, dissepiment entire to lacerate, thin. Context with two black lines, fibrous, 0.1–0.2 mm thick, cream (B 2). Tubes concolorous to the hymenial surface, approximately 0.1 mm deep. Hyphal system dimitic, generative hyphae hyaline, clamped, thin-walled, 2–3 μm diam.; skeletal hyphae hyaline to yellow, arboriform, thick-walled to solid, 3–6 μm diam., IKI- to IKI+ Hyphal pegs absent. Basidia not observed. Basidiospores subglobose to globose, yellow in KOH, thick-walled, distinctly ornamented 11–14 × 10–13 μm, IKI- to slightly IKI+.

Substrate: —in dead hardwood.

Distribution: —only known from the States of Amazonas, Mato Grosso and Pará in the Brazilian Amazonia.

Specimens examined: — BRAZIL. Amazonas: Rio Purus, Rio Ituxi , vicinity of Boca de Curuquete , July 1971, Prance et al. 14075 ( INPA 32290 ), Jutaí, Estação da SEMA, October 1986, E. S. S. Silva et al. 859 ( INPA 154974 ) ; Mato Grosso, Aripuanã , April 1978, M. A. Sousa 467 ( INPA 75622 ) .

Remarks: —Among the species of the genus, only A. africana Ryvarden (2004b: 57) , A. andina Ryvarden (2004b: 59) and A. flabellatum Aime & Ryvarden (2007: 16) were known to have sessile basidiomata growing on dead wood. However, A. flabellatum has slightly smaller pores (7–9/mm); A. africana has larger (14–18 ×10–14 μm), while A. andina and A. flabellatum have smaller basidiospores (8–10 μm in the former, 7–8 × 6.5–7.5 μm in the latter) and homogeneous context ( Ryvarden 2004 a, Aime et al. 2007). The new species A. subsessile also grows in dead wood, but it has a short to long stipe.

Figures

FIGURE 11. Amauroderma sessile (INPA 103576). A. Basidioma. B. Hymenial surface. C. Basidiospores in KOH. Scale: A, C = 1 cm; B = 10 μm. Photos: A.C. Gomes-Silva.