Candolleomyces candolleanus

(3.1) Candolleomyces candolleanus complex Notes:— In the ITS-only phylogeny (Fig. 4B), 20 collections of ours and 32 collections representing 20 legitimately proposed species established a large monophyletic group with low internal pairwise variations (generally less than 1%), although without significant support. In the four-locus phylogeny (Fig. 4A), this group was represented by 21 collections and received significant support from the ML analysis. The two phylogenies together suggest a large species complex comprising at least 20 legitimately proposed species, referred to as the Candolleomyces candolleanus complex in this study, characterized by basidiomata that are usually not caespitose, with a whitish to yellowish pileus, and a typically terrestrial, sometimes lignicolous habit. Three other species, namely Cd. subcandolleanus, Cd. thailandensis and Cd. yanshanensis, also belong to this complex according to their morphology and previously reported phylogenetic analyses (e.g., Bhunjun et al. 2022, Zhou et al. 2022, Nayana & Pradeep 2024). However, during the preparation of our phylogenetic analyses, we observed that the ITS sequences from their type collections exhibited unusual variability in the 5.8S region. As a result, these sequences were excluded from our analyses (Fig. 7; Supplement 11). Similar sequences could be reproduced by multiple-peak sequencing results. Legitimately proposed species recognized in this complex:— Cd. albosquamosus P.K. Nayana & C.K. Pradeep (2023, holotype sequenced), Cd. badhyzensis (Kalamees) D. Wächt. & A. Melzer (2020, holotype sequenced), Cd. badiophyllus (Romagn.) D. Wächt. & A. Melzer (2020), Cd. bivelatus (Contu) D. Wächt. & A. Melzer (2020), Cd. brevisporus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. candolleanus (Fr.) D. Wächt. & A. Melzer (2020, neotype sequenced), Cd. cladii-marisci (Sicoli et al.) N.G. Passal. & Sicoli (2023, holotype sequenced), Cd. crenatus Haqnawaz, Niazi & Khalid (2025, holotype sequenced), Cd. duboissoniae Y.P. Tan, Bishop-Hurley & Marney (2024, holotype sequenced), Cd. gyirongicus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. incanus C.L. Hou & Hao Zhou (2022, holotype sequenced), Cd. lignicola R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. luridus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. niveosquamosus Nayana & C.K. Pradeep (2024, holotype sequenced), Cd. pseudocandolleanus (A.H. Sm.) D. Wächt. & A. Melzer (2020), Cd. rogueianus (recombined below (see subsection 3.5), holotype sequenced), Cd. shennongdingicus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. shennongjianus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. sichuanicus R.L. Zhao, B. Cao & X.X. Han (2024, holotype sequenced), Cd. subcandolleanus C.L. Hou & Hao Zhou (2022, holotype sequence suspect), Cd. thailandensis Suwannar., Kumla & Lumyong (2022, holotype sequence suspect), Cd. trinitatensis (R.E.D. Baker & W.T. Dale) D. Wächt. & A. Melzer (2020), and Cd. yanshanensis C.L. Hou & Hao Zhou (2022, holotype sequence suspect). Collections sequenced in this study:— China, Guangdong Province, Guangzhou City and Foshan City, elevation 5–150 m, 2023–2024, Jia Y. Lin, Kun L. Yang & Zhen-Chao Liu, K23125 (HTBM0640), K23240 (HTBM0755), K23284 (HTBM0799), K23285 (HTBM0800), K23307 (HTBM0822), L2371 (HTBM0904), L23376 (HTBM1357), L23388 (HTBM1369), L23397 (HKAS145960, partially isolated as HTBM1378), L23418 (HTBM1399), S23437 (HTBM1548), L24067 (HTBM1941), L24177 (HTBM2162), L24184 (HKAS145962, partially isolated as HTBM2169, results discarded by multipeaks), L24185 (HTBM2170, results discarded by multipeaks), L24186 (HTBM2171, results discarded by multipeaks), L24187 (HTBM2172), L24188 (HKAS145961, partially isolated as HTBM2173), L24189 (HTBM2174), L24190 (HTBM2175), L24191 (HTBM2176), L24199 (HTBM2184) and L24200 (HTBM2185).