Hydnophanerochaete odontoidea (Sheng H. Wu) Sheng H. Wu & C.C. Chen

Chen, Che-Chih, Wu, Sheng-Hua & Chen, Chi-Yu, 2018, Hydnophanerochaete and Odontoefibula, two new genera of phanerochaetoid fungi (Polyporales, Basidiomycota) from East Asia, MycoKeys 39, pp. 75-96 : 75

Hydnophanerochaete odontoidea (Sheng H. Wu) Sheng H. Wu & C.C. Chen comb. nov. Figs 3aand 4

Basionym.

Phanerochaete odontoidea Sheng H. Wu, Botanical Bulletin of the Academia Sinica 41: 169, 2000.

Synonym.

Phanerochaete subodontoidea Sheng H. Wu, Botanical Bulletin of the Academia Sinica 41: 172, 2000.

Holotype.

TAIWAN. Ilan: Fushan Botanical Garden, 24°46'N, 121°35'E, 600 m alt., on fallen branch of angiosperm, leg. S.H. Wu et al., 7 Aug 1991, Wu 910807-11 (TNM F14816).

Description.

Basidiocarps annual, effused, adnate, ceraceous, somewhat brittle, 50-200 μm thick in section (aculei excluded). Hymenial surface initially buff, with age turning ochraceous to pale brown, no colour changes in KOH, tuberculate to grandinioid when young, becoming odontioid to hydnoid with age, extensively cracked; margin paler to whitish, fairly determinate. Aculei conical to cylindrical, usually separate, with obtuse to acute apex, 1-4 per mm, up to 100-700 × 100-250 μm.

Hyphal system basically monomitic, some specimens with quasi-binding hyphae near substratum; generative hyphae simple-septate. Subiculum fairly uniform, composed of a basal layer of compact texture; generative hyphae mainly horizontal, colourless, 4-6 μm diam., with 0.8-1 µm thick walls; quasi-binding hyphae sometimes present near substratum, colourless, 1-3 µm diam. Hymenial layer thickening, with compact texture, generative hyphae somewhat vertical, colourless, 3-6 μm diam., slightly thick-walled. Trama of aculei of compact texture; generative hyphae mainly vertical, other features similar to those in subiculum; crystal masses present near apex. Cystidia lacking, but projecting hyphal ends in the hymenium may be present. Basidia clavate, 14-18 × 4.5-5.5 μm, 4-sterigmate. Basidiospores narrowly ellipsoid to cylindrical, adaxially slightly concave, smooth, thin-walled, homogeneous, inamyloid, non-dextrinoid, acyanophilous, 6-8.1 × 2.5-3.3 μm (Table 2). See also Wu (2000) for descriptions and illustrations.

Habitat.

On fallen branches of angiosperms or gymnosperms.

Distribution.

Hitherto known from subtropical to temperate regions of China (Yunnan), Japan, Taiwan and Vietnam.

Additional specimens examined.

CHINA. Yunnan: Diqing Tibetan Autonomous Prefecture, Deqin County, Xiayubeng Village, Shenhu Trail, 3500 m alt., on fallen branch of gymnosperm, leg. C.C. Chen, 14 Aug 2013, GC 1308-45 (TNM F27660). JAPAN. Honshu: Nagano Prefecture, Nagano City, Myoko-Togakushi Renzan National Park, 36°45 ’35” N, 138°04 ’20” E, 1235 m alt., on branch of Quercus sp., leg. C.C. Chen & C. L. Chen, 29 July 2016, GC 1607-20 (TNM F30785). TAIWAN. Chiayi: Yushan National Park, Nanhsi Forest Road, 23°28'N, 120°54'E, 1850 m alt., on fallen branch of angiosperm, leg. S.H. Wu & S.Z. Chen, 13 Oct 1993, Wu 9310-8 (paratype of P. odontoidea , TNM F14824); Wu 9310-29 (TNM F14826); 1800 m alt., on fallen branch of angiosperm, leg. S.H. Wu & S.Z. Chen, 13 Jun 1996, Wu 9606-55 (TNM F5085). Ilan: Fushan Botanical Garden, 24°46'N, 121°35'E, 650 m alt., on fallen branch of angiosperm, leg. S.H. Wu et al., 28 Jun 2002, Wu 0106-35 (TNM F13460). Nantou: Tungpu Township, Leleku, 1450 m alt., on fallen rotten wood, leg. W.N. Chou, 13 Apr 1994, CWN 00776 (holotype of P. subodontoidea , TNM F14836). Kaohsiung: Maolin District, Tona Nursery, 22°54'N, 120°44'E, 850 m alt., on fallen branch of angiosperm, leg. S.Z. Chen, 31 Mar 2005, Chen 1376 (TNM F18764). New Taipei: Chinshan District, Yangmingshan National Park, Yulu Historical Trail, 25°10'N, 121°35'E, 516 m alt., on fallen branch of angiosperm, leg. C.C. Chen, C.L. Wei, W.C. Chen & S. Li, 26 Aug 2015, WEI 15-309 (TNM F29370); WEI 15-348 (TNM F29384). Taichung: Chiapaotai, 850 m alt., on fallen branch of angiosperm, leg. S.H. Wu, 6 Dec 1991, Wu 911206-38 (paratype of P. subodontoidea , TNM F14818). VIETNAM. Lam Dong: Bi Doup Nui Ba National Park, 12°10 ’45” N, 108°40 ’48” E, 1447 m alt., on fallen branch of angiosperm, leg. C.C. Chen, 15 Oct 2017, GC 1710-59 (TNM F31365).

Remarks.

Phanerochaete subodontoidea morphologically resembles Phanerochaete odontoidea , whereas they were distinguished merely based on the width of basidiospores [ P. odontoidea : 2.6-3 µm vs. P. subodontoidea : 3-3.7 µm, Wu (2000)]. However, after carefully measuring the basidiospore size of available specimens of these two species, we found basidiospore ranges are highly overlapping (Table 2). Additionally, the ITS sequences of the holotype of P. subodontoidea (CWN 00776) is almost identical to the ITS sequences of the paratype of P. odontoidea (Wu 9310-8). We failed to obtain sequences from the holotype of P. odontoidea (Wu 910807-11), but Wu 9310-8 was confirmed as conspecific with the holotype by morphological comparison. Thus, based on morphological and molecular evidence (Fig. 2), P. subodontoidea is treated as a synonym of P. odontoidea . A paratype specimen named P. odontoidea (Wu 9311-46) probably belongs to the genus Flavodon Ryvarden based on preliminary BLAST results of nuc 28S sequences. However, this specimen was not included in this study.