Nigrofomes sinomelanoporus L.W. Zhou

Zhou, Li-Wei, Wang, Xue-Wei, Vlasak, Josef & Ren, Guang-Juan, 2018, Resolution of phylogenetic position of Nigrofomitaceae within Hymenochaetales (Basidiomycota) and Nigrofomessinomelanoporus sp. nov. (Nigrofomitaceae) from China, MycoKeys 29, pp. 1-13 : 4-5

Nigrofomes sinomelanoporus L.W. Zhou sp. nov. Figs 3, 4

Holotype.

CHINA. Hainan Province, Baisha County, Yinggeling National Nature Reserve, 17 Nov 2015, on dead standing angiosperm tree, Dai 16286 (BJFC 020373, isotype in IFP 019162).

Etymology.

Sinomelanoporus (Lat.): referring to the Chinese specimens similar to Nigrofomes melanoporus .

Description.

Basidiocarps perennial, effused-reflexed, pileate, solitary, without odour or taste when fresh, woody hard. Pilei triquetrous or applanate, fan-shaped to semicircular, projecting up to 7 cm long, 15 cm wide and 4 cm thick at base. Pileal surface dark brown to black, rimose with age, glabrous to tuberculate, distinctly concentrically zonate and sulcate with a distinct crust; margin sharp, black. Pore surface mouse-grey to vinaceous grey, glancing; sterile margin vinaceous brown, up to 5 mm wide; pores angular, 7-9 per mm; dissepiments thin, entire to slightly lacerated. Context vinaceous grey, woody hard, distinctly concentrically zonate, upside integrating with a distinct crust on the pileal surface, up to 1 cm thick. Tubes greyish brown to vinaceous grey, the fresh layer dark grey to black, woody hard, up to 3 cm long.

Hyphal system pseudodimitic; generative hyphae simple septate; all hyphae inamyloid, indextrinoid, acyanophilous; tissue unchanged in KOH. Context: generative hyphae hyaline to pale brown, slightly thick- to thick-walled with a wide lumen, rarely branched, frequently septate, 3-5 µm diam; skeletal-like hyphae dominant, pale brown, thick-walled with a wide lumen to subsolid, unbranched, occasionally septate, straight, more or less regularly arranged, 4.5-6 µm diam. Tubes: generative hyphae hyaline to pale brown, thin-to slightly thick-walled with a wide lumen, rarely branched, frequently septate, 2-5 µm diam; skeletal-like hyphae pale brown, thick-walled with a wide lumen to subsolid, unbranched, rarely septate, straight, more or less parallel along the tubes, 3.5-5 µm diam. Cystidia and cystidioles absent; basidia broadly ellipsoid to barrel-shaped, with four sterigmata and a simple septum at the base, 8-10 × 6.5-7.5 µm; basidioles in shape similar to basidia, but slightly smaller; basidiospores broadly ellipsoid to subglobose, hyaline, thin-walled, inamyloid, indextrinoid, acyanophilous, (4.5 –)4.8–6(– 6.7) × (3.8 –)4–4.8(– 5) µm, L = 5.18 µm, W = 4.27 µm, Q = 1.17-1.27 (n = 120/4).

Additional specimens (paratypes) studied.

CHINA. Hainan Province, Changjiang County, Bawangling National Nature Reserve, 25 Nov 2010, on dead standing tree of Pentaphylax euryoides , Dai 12034 (BJFC 009087, a duplicate in IFP 019163); Lingshui County, Diaoluoshan National Forest Park, 20 Nov 2007, on fallen angiosperm trunk, Cui 5277 (BJFC 003316, a duplicate in IFP 019164), Cui 5282 (BJFC 003321, a duplicate in IFP 019165).

Other specimens studied.

Nigrofomes melanoporus . COSTA RICA. Puntarenas Province, La Gamba Town, Piedras Blancas National Park, 20 Apr 2015, on fallen angiosperm trunk, Vlasák 1504/42 (JV, a duplicate in IFP 019166); Alajuela Province, Bijagua, Catarata Trail, 28 July 2016, on fallen angiosperm trunk, Vlasák 1607/82 (JV, a duplicate in IFP 019167); Puntarenas Province, Golfito Town, Playa Nicuesa Rainforest Lodge, 18 Apr 2017, on fallen angiosperm trunk, Vlasák 1704/39 (JV, a duplicate in IFP 019168; Fig. 5).

Note.

Nigrofomes sinomelanoporus differs by broadly ellipsoid to barrel-shaped basidia, absence of cystidia and larger basidiospores from N. melanoporus , which has clavate basidia, rare cystidia and smaller basidiospores (4-5 × 3-3.5 µm; Ryvarden 2015).

Regarding the hyphal system of N. melanoporus , Ryvarden (2015) recognised it as "probably dimitic" and Lowe (1966) as “dimitic”. They both mentioned the so-called skeletal hyphae are sometimes septate. According to the authors’ observations, there are two kinds of hyphae present in N. melanoporus and N. sinomelanoporus and one of them is frequently septate, whereas the other rarely or occasionally septate. When describing this kind of hyphal system, we prefer “pseudodimitic” to “dimitic” because genuine skeletal hyphae are generally defined as aseptate.