Fungalpedia – Note 63 Acanthofungus
Acanthofungus Sheng H. Wu, Boidin & C.Y. Chien
Citation if using this entry: Bera et al. (2023) Basidiomycota. Mycosphere (in prep)
The whitish, resupinate, pulvinate, and deeply cracked basidiomata of this wood-decaying basidiomycete is reminiscent of Xylobolus frustulatus (Pers.) P. Karst (Wu et al. 2000). After being documented first from an endemic gymnosperm tree (Calocedrus formosna) in Taiwan, monosporous and polysporous cultures were prepared (Wu et al. 2000). Based on the cultural and morphological characteristics, Acanthofungus was introduced, and typified by A. rimosus Sheng H. Wu, Boidin & C.Y. Chien under the family Stereaceae (Wu et al. 2000). The appearance of the basidiomata is composed of many orbicular patches and pieces (Wu et al. 2000). The hymenium shows distinct thickening with a compact texture and composed of vertical, colourless compactly arranged hyphae (Wu et al. 2000). This genus has numerous thick-walled, tubular to cylindrical shaped gloeocystidia which are mostly colourless but brownish towards the matured hymenial surfaces (Wu et al. 2000). The acanthophyses are clavate to cylindrical shaped with acute to obuse apices and are arranged in palisade manner in hymenial and lateral surfaces (Wu et al. 2000). The basidiospores are thin-walled, ellipsoid-shaped, colourless to brownish, acyanophilous, and bluish black in Melzer’s reagent (Wu et al. 2000). The polysporous culture showed white mat growth of colony with no aerial mycelium, and colourless, nodose-septate advancing hyphae (Wu et al. 2000). Another genus, Acanthophysellum Parmasto is quite similar to Acanthofungus but the white pocket rot and the negative phenoloxidase reaction of the latter differentiate the two genera (Wu et al. 2000). Similarly, Stereum ahmadii Boidin can be distinguished based on its smaller-sized basidiospores despite being alike to Acanthofungus (Wu et al. 2000). Therefore, Wu et al. (2000) accommodated Acanthophysellum thoenii, Stereum ahmadii under Acanthofungus as Acanthofungus thoenii, and A. ahmadii. Currently, there are only three species documented under this genus.
Type species: Acanthofungus rimosus Sheng H. Wu, Boidin & C.Y. Chien
Other accepted species: A. ahmadii (Boidin) Sheng H. Wu, Boidin & C.Y. Chien
A. thoenii (Boidin, Lanq. & Gilles) Sheng H. Wu, Boidin & C.Y. Chien
Fig 1. Acanthofungus rimosus (holotype) a. Young basidiomata forming small patches on woody substratum. b. Basidiospores. c. Basidia. d. Acanthophyses. e. Gloeocystidia. Scale bars: b-e = 10 μm. Drawn from Wu et al. 2000.
Wu SH, Boidin J, Chien CY 2000 – Acanthofungus rimosus gen. et sp. nov., with reevaluation of the related genera. Mycotaxon, 76, 153–161. http://www.cybertruffle.org.uk/cyberliber/59575/0076/0158.htm
Ishika Bera, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand
(Edited by Kevin D Hyde)