Ganoderma oerstedii Murrill, Bull. Torrey bot. Club 29: 606 1902
Creators: name: Mardones, Melissa
name: Carranza-Velazquez, Julieta
name: Mata-Hidalgo, Milagro
name: Amador-Fernandez, Xaviera
name: Urbina, Hector
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Basidiomycetes
Polyporales
Polyporaceae
Ganoderma
Ganoderma oerstedii

description: 6. Ganoderma oerstedii (Fr.) Murrill, Bull. Torrey bot. Club 29: 606 (1902)  
Figs 3H, 8  
 = Ganoderma tuberculosum Murrill, N. Amer. Fl. (New York) 9(2): 123 (1908). Type: BELIZE (as British Honduras), 1906, M.E. Peck s.n. (holotype: BPI236681!).   
Type.  
 Costa Rica: s. l., 1846, Oersted. s.n. (neotype: BPI236610!).   
Descriptions.  
 Basidiocarps gregarious, solitary or imbricate, mostly sessile, sometimes laterally stipitate, dimidiate, ungulate or spathulate woody, rugulose, 2.8-19.1 × 2.1-24.5 × 0.7-3.9 cm; pileus surface with laccate zones, glabrous, zonate, brownish-red, vinaceous-brown, vinaceous-red, yellowish-red, gradually changing to yellowish-brown to deep yellow in the margin, margin obtuse; context firm, yellowish-brown, up to 6 cm thick, concentrically zonate, with inconspicuous horizontal bands of melanoid substances; pore surface yellowish-brown to pinkish-brown, darkening when handled, pores circular to irregular, 3-6 per mm; tube layers light brown to yellowish-brown, up to 0.9 cm thick, becoming darker with 5% KOH. Stipe glabrous, vinaceous-red or concolorous with pileus surface, with some laccate zones, 1.5-13.1 × 1.2-7.5 cm. Hyphal system dimitic or trimitic; contextual generative hyphae thick-walled, with clamps, hyaline, 5 µm in diam.; skeletal hyphae thick walled 3-9 µm in diam.; binding hyphae thin and thick-walled, 2-4 µm in diam. Cuticular cells from the pileus cylindrical, clavate, some nodulose, vesiculate and branched, thick-walled, with granulations in the apex, yellowish, with strong amyloid reaction with Melzer’s Reagent, 22-52(-100) × 6-20 µm. Basidia not observed. Basidiospores ovoid, truncate at the distal end; with two walls, connected by inter-wall pillars, subhyaline or yellowish-brown, negative in Melzer’s Reagent, (8-)11-14(-15) × (5-)8-11 µm. Chlamydospores thick-walled, reddish-brown, 23-30 × 16-21 µm.   
Descriptions and illustrations.  
 Murrill (1902, 1908 as G. tuberculosum), Steyaert (1980), Gottlieb and Wright (1999b as G. tuberculosum), Ryvarden (2000, 2004), Mendoza et al. (2011), Torres-Torres et al. (2015), Lopez-Peña et al. (2016).   
Substrata.  
On living trees and logs.  
Altitudinal distribution.  
Lowlands to highlands.  
Geographic distribution.  
Widespread in the Neotropics.  
Specimens examined.  
Costa Rica. Alajuela: Grecia, Santa Gertrudis, 10°5'13.94"N, 84°17'3.96"W, 1050 m elev., 14 Jul 1991, J. Carranza JCV 16-91 (USJ33286). Guanacaste: Abangares, Higuerillas, Finca El Arboreto, 10°11'28.28"N, 85°3'10.8"W, 0-100 m elev., 20 Jun 2007, J.A. Sáenz 2049 (CR4095735); La Cruz, Parque Nacional Guanacaste, Estación Biológica Cacao, sendero Los Naranjos, 10°53'43.2"N, 85°28'24.6"W, 700-1000 m elev., 23 May 1997, E. Fletes and C. Cano 1112 (CR4130985); Santa Cruz, Reserva Ramón Alvarez, 10°17'20.4"N, 85°35'13.2"W, 0-100 m elev., 24 Sep 2011, J. Carranza JCV 7-11 (USJ83002). Heredia: Santo Domingo, San Luis, 10°0'16.4"N, 84°1'44.7"W, 1200 m elev., 06 Nov 2016, J. Carranza JCV 1-16 (USJ109683). Limón: Talamanca, Refugio de Vida Silvestre Gandoca- Manzanillo, sector Manzanillo, alrededores del Centro Operativo, 9°38'19.6"N, 82°38'56.6"W, 0-100 m elev., 26 Sep 2001, R. Valladares RValladares 555 (CR3468098). Puntarenas: Coto Brus, San Vito, Área de Conservación La Amistad Pacífico, Zona Protectora Las Tablas, Fila Chiquizá, 8°55'34.4"N, 82°46'00.95"W, 1500-1600 m elev., 19 Jul 2002, E. Navarro 5006 (CR3516656); Osa, Parque Nacional Marino Ballena, Finca Roca, a orillas de la playa, 9°9'9.02"N, 83°44'46.9"W, 0-100 m elev., 21 Jan 2004, E. Fletes 5876 (CR3813349). San José: Montes de Oca, San Pedro, Universidad de Costa Rica, Finca 1, estacionamiento del CIICLA, 9°56'19.5"N, 84°3'9.4"W, 1100 m elev., 11 Sep 2019, J. Carranza GA-21 (USJ109786); 9°56'19.5"N, 84°3'9.34"W, 1100 m elev., 18 Dec 2019, J. Carranza GA-24 (USJ109787, sequences ITSOQ845469).   
Discussion.  
This species was originally described from Costa Rica. It is characterised by its woody basidiocarp, reddish-brown in the base, to deep yellow in the margin. The species has a yellowish-brown context, with continuous resinous bands and clavate, branched and vesiculate cuticular cells with strong amyloid reaction with Melzer’s Reagent. The two walls in the basidiospores are connected by inter-wall pillars.   
 The piece of the neotype specimen examined under Polyporus oerstedii Fr. - G. oerstedii (Fr) Murr., collected in Costa Rica, only contained a small portion of the tubes with abundant ovoid, truncate, echinulate spores, 9.3-13.6 × 7.65-9.3 µm. Annotations done by O. Juel, Xin-Cun Wang, Donjmei Wang and Ryvarden mentioned spores 9-10 × 6.5-8 µm (with wall 11-12 µm), 11.5-13 × 8.5-10.5 µm, 11.5-15 × 8-11.5 µm (with wall), 10-13.5 × 6.5-10.5 µm (without wall) and 11-14 × 7-10 µm, respectively. The spores in the specimens studied from Costa Rica are in the range of the ones found on the neotype and the ones mentioned by the above researchers.   
 In taxonomic studies by Ryvarden (2000) and Torres-Torres et al. (2015) and in Mycobank (https://www.mycobank.org/), G. oerstedii is considered a synonym of G. tuberculosum, although newer studies by Loyd et al. (2018) and Fryssouli et al. (2020), as well as Index Fungorum contradicted them. We examined the type specimens of both taxa and significant morphological differences were not observed; hence, we concluded that these taxa are co-specific.   
 According to Loyd et al. (2018), G. tuberculosum generally produced sessile basidiomata. However, amongst Costa Rican specimens, we found two forms: sessile and laterally stipitate basidiomes. Additionally, Loyd et al. (2018) mentioned that chlamydospores were lacking in the species, although they are presented in our collections.   
 The sequences from Costa Rican specimens GA-24 and JV1607/62 (retrieved from GenBank, MZ354944) strongly supported a terminal subclade (1/99), together with other sequences labelled as G. tuberculosum or G. oerstedii collected from Brazil, Florida (USA) and Mexico, within clade I that also includes the species G. Ganoderma philippii, G. flexipes and G. wiiroense.
description: Published as part of Mardones, Melissa, Carranza-Velazquez, Julieta, Mata-Hidalgo, Milagro, Amador-Fernandez, Xaviera & Urbina, Hector, 2023, Taxonomy and phylogeny of the genus Ganoderma (Polyporales, Basidiomycota) in Costa Rica, pp. 5-47 in MycoKeys 100 on page 5, DOI: 10.3897/mycokeys.100.106810