Inonotus shoreicola – Facesoffungi number: FoF 02052

Inonotus shoreicola L.W. Zhou, Y.C. Dai & Vlasák

Index Fungorum number: IF 551555 Facesoffungi number: FoF 02052.

Etymology: refers to the host genus Shorea. Holotypus: LWZ 20140728-10 (IFP)

Basidiocarps perennial, sessile, single, ungulate, woody hard, without Odour and taste when dry. Pileus dimidiate, projecting up to 7 cm, 20 cm wide and 8 cm thick at base. Pileal surface pale mouse-grey to vinaceous grey, radially cracked, concentrically zonate and sulcate; margin obtuse, ash-grey. Pore surface dark brown, slightly glancing; sterile margin distinct, yellowish brown, up to 5 mm; pores circular to angular, 7 per mm; dissepiments thin, entire. Context dark brown, woody hard, up to 4 mm. Tubes yellowish brown, woody hard, tube layers distinctly stratified, annual layer about 5 mm long; white mycelial strands present in old tubes.

Hyphal system monomitic; generative hyphae simple septate; tissue darkening but otherwise unchanged in KOH. Contextual generative hyphae yellowish, thick-walled with a wide lumen, rarely branched, simple septate, interwoven, acyanophilous, 1–2.5μm in diam. Tramal generative hyphae yellowish, slightly thick- to thick-walled with a wide lumen, occasionally branched, simple septate, parallel along the tubes, acyanophilous, 2–3μm in diam. Hyphoidsetae absent; hymenialsetae occasionally present, subulate to ventricose, dark brown,thick-walled, sharp pointed, sometimes with an elongated base, 15–38×8–20μm; cystidia and cystidioles absent; basidia and basidioles not seen; rhomboid crystals present in hymenium.

Basidiospores broadly ellipsoid, yellowish, slightly thickwalled, neither amyloid nor dextrinoid, cyanophilous, (4.4–)4.6–5.1(–5.4)×(3.2–)3.5–3.9(–4) μm, L=4.86μm, W=3.75μm, Q=1.29–1.3(n=60/2)

Material examined: THAILAND, Chiang Mai Province, Sri Lanna National Park, Mae Taeng Forests, on living tree of Shorea, 28 July 2014, LWZ20140728-10 (IFP, holotype), LWZ 20140728-23 (IFP); Ibid., 21 October 2013, Dai 13614 (BJFC), Dai 13615 (BJFC), 29 July 2014, LWZ 20140729-1 (IFP).

Notes: Zhou et al. (2016a) identified three clades within Inonotus and also several species of Inonotus outside the three clades. The clade, including the generic type Inonotus hispidus, was considered to be Inonotus sensu stricto, while the other two clades were introduced as new genera Sanghuangporus and Tropicoporus; the species outside any clade were also accommodated in Inonotus sensu stricto for they have key characters of Inonotus (Zhou et al. 2016a). The current phylogeny shows that Inonotus shoreicola is close to Inonotus sensu stricto, Sanghuangporus and Tropicoporus. Moreover, Inonotus shoreicola fits well with the morphological concept of Inonotus sensu Dai (2010). Therefore, we place species in Inonotus. Inonotus shoreicola resembles the pileate members of Sanghuangporus and Tropicoporus in its perennial basidiocarps, cracked pileal surfaces and coloured basidiospores; however, these two genera are distinguished by having dimitic hyphal system at least in trama (Zhou et al. 2016a), while Inonotus shoreicola has a monomitic hyphal system in both context and trama. Inonotus pachyphloeus (Pat.) T. Wagner & M. Fisch. also has perennial basidiocarps and a monomitic hyphal system as I. shoreicola, but differs in the presence of hyphoid setae (Fidalgo 1968; Dai2010). Some pileate species of Fomitiporia Murrill, such as F. hartigii (Allesch.&Schnabl) Fiasson&Niemelä and F. robusta (P.Karst.) Fiasson&Niemelä, also have cracked pileal surfaces (Dai 2010), which make them similar to I. shoreicola especially in the field. However, in micromorphology, Fomitiporia is characterized by a dimitic hyphal system and hyaline, dextrinoid basidiospores (Dai 2010). Inonotus shoreae (Wakef.) Ryvarden, originally described from India, also inhabits Shorea like I. shoreicola, and is a serious parasite on roots and butts of Shorea (Sharma 1995). These two species could be easily differentiated in the field: I. shoreae has annual basidiocarps with much larger pores (2–4 per mm, Sharma 1995). Moreover, Inonotus shoreae has shorter basidiospores (3.5–5×2.5–3μm) than I. shoreicola (Sharma 1995). Itis noteworthy that I. shoreicola is relatively common and has been considered to be a medicinal fungus in Thailand.