Irpex jinshaensis Z.B. Liu, X.M. Tian & Y.C. Dai, 2022

Tian, Xue-Mei, Man, Xiao-Wu & Liu, Zhan-Bo, 2022, Irpex jinshaensis sp. nov. and I. subulatus comb. nov. (Irpicaceae, Polyporales), evidenced by morphological characters and phylogenetic analysis, Phytotaxa 533 (1), pp. 73-82 : 77-79

Irpex jinshaensis Z.B. Liu, X.M. Tian & Y.C. Dai , sp. nov. ( Figs. 2–3 )

MycoBank no.—MB 841367

Diagnosis:— Irpex jinshaensis is characterized by an annual growth habit, resupinate basidiocarps with white to cream pores when fresh becoming salmon to cinnamon upon drying, a monomitic hyphal system, generative hyphae thickwalled with simple septa, and occasionally covered with small crystal granules, the presence of encrusted cystidia and broadly subglobose to globose basidiospores.

Etymology:—‘ jinshaensis ’ (Lat.): refers to the valley of the Jinsha River, where the holotype was collected.

Type:— CHINA. Yunnan Province, Shuifu County, Tongluoba Forest Park , on fallen angiosperm branch, 1 July 2021, Y.C. Dai, Dai 22402 (Holotype, BJFC) .

Description:—Basidioma annual, resupinate, cushion-shaped, closely adnate, soft corky when fresh, becoming hard corky upon drying, up to 8 cm long, 2.5 cm wide, and 0.25 mm thick; margin distinct, white, fimbriate, thinning out; pore surface white to cream when fresh, becoming salmon to cinnamon when dry; pores angular, 4–6 per mm; dissepiments thin, entire to slightly lacerate; subiculum very thin to almost absent; tubes concolorous with poroid surface, less than 1 mm long.

Hyphal structure:—Hyphal system monomitic; generative hyphae thick-walled, simple septate; all hyphae IKI–, CB+, unchanged in KOH.

Subiculum:—Generative hyphae hyaline, thick-walled, frequently branched, interwoven, often filled with oily contents, occasionally covered with small crystal granules, 3–5 μm in diam; oily materials scattered throughout the subiculum.

Tubes:—Generative hyphae hyaline, thick-walled, often branched, interwoven, occasionally covered with small crystal granules, 2–4 μm in diam, narrower than those of subiculum; cystidia conspicuous, abundant, mostly as true thick-walled hymenial cystidia arising from basidial side branches, up to 43 µm long and 5 µm wide, cylindrical to conical, apically heavily incrusted, but also as generative hyphae emerging into the hymenium with an apical encrustation, arising deeply from the trama, the transitions between these two types or forms present, incrusted part 8–32 × 3–7 μm; basidia clavate, hyaline, thin-walled, bearing four sterigmata and a simple basal septum, flexuous, 16–18 × 4–5 μm; basidioles similar in shape to basidia, but slightly shorter.

Basidiospores:—Subglobose to globose, hyaline, thin-walled, smooth, IKI–, CB–, 4–5 × 3.5–4 μm, L = 4.28 μm, W = 3.75 μm, Q = 1.14 (n = 60/1).

Figures

FIGURE 2. Basidiocarp of Irpex jinshaensis (Holotype, Dai 22402). Scale bar = 1.0 cm. Photo by: Yu-Cheng Dai.

FIGURE 3. Microscopic structures of Irpex jinshaensis (Holotype, Dai 22402). a Basidiospores; b Basidia and basidioles; c Cystidia; d Hyphae from subiculum; e Hyphae from trama. Drawings by: Zhan-Bo Liu.