Ganoderma curtisii (Berk.) Murrill, N. Amer. Fl. (New York) 9(2): 120 (1908).

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, MycoKeys 100, pp. 5-47 : 5

4. Ganoderma curtisii (Berk.) Murrill, N. Amer. Fl. (New York) 9(2): 120 (1908).

Figs 3E, F , 6

≡ Polyporus curtisii Berk. 1849.

Type.

USA, South Carolina, s.d., s.n. (type: PH 00042681) .

Descriptions.

Basidiocarps solitary, laterally and long stipitate, reniform, dimidiate or circular, 10.5-11.1 × 6.3-9.9 × 0.7-2.5 cm; pileus single or several arising from a branching stipe, cespitose, glabrous, shiny both when fresh and dry, laccate, upper surface yellow, yellowish-brown to reddish-brown with purple hues; context firm, buff to light brown, duplex, without concentric growth zones, 7-13 mm thick, with continuous melanoid bands embedded in context tissue, originating from the stipe and running parallel to the upper surface; pore surface pinkish-brown to yellowish, darkening when handled, pores circular to irregular, 4-6 per mm; tube layers ochraceous-tawny, 10-12 mm thick. Stipe lateral, 30-250 mm long, round, or slightly compressed, 12-18 mm diam. and with a purple to black, shiny cuticle. Hyphal system trimitic; contextual generative hyphae thick-walled, with clamps, hyaline, 3.5 µm in diam.; skeletal hyphae thick-walled, 1.5-6 µm in diam., light yellow; binding hyphae thin and thick-walled, 3-5 µm in diam. Cuticular cells from the pileus clavate, some nodulose, sometimes with 1 to 2 protuberances, rarely branched, with granulations in the apex, yellowish, with strong amyloid reaction with Melzer’s Reagent, 45-55 × 9-14 µm. Basidia not observed. Basidiospores ellipsoid to oblong, truncate at the distal end; with two walls, yellowish-brown to brown, moderately coarsely echinulate, (9-)11-17 × (7-)8-10 µm. Chlamydospores not observed.

Descriptions and illustrations.

Torres-Torres and Guzmán-Dávalos (2005, 2012), Lopez-Peña et al. (2016).

Substrata.

On Quercus spp. or Pinus spp., on decaying wood.

Altitudinal distribution.

In Costa Rica, this species is found only in the highlands.

Geographic distribution.

Mexico and the USA. This is the first report in Costa Rica and Central America.

Specimens examined.

Costa Rica. Alajuela: Grecia, Reserva Forestal Grecia, Bosque del Niño, sendero al acueducto, 10°8'30.90"N, 84°14'49.39"W, 1800-1900 m elev., 26 Jun 2006, E. Navarro 10132 (CR4089789); on soil, 10 Jul 2016, M. Mata 2647 (USJ109166). Cartago: Paraíso, Reserva Forestal Rio Macho , Villa Mills , finca Los Abarca , 31 Aug 2008, 9°34'11.15"N, 83°42'37.40"W, 2600-2700 m elev., E. Alvarado 417 (CR4164678); Sector La Chonta , km. 55 de la carretera Interamericana Sur , 9°42'00.0"N, 83°56' 30.0"W, 2400-2500 m elev., 20 Jul 2007, E. Navarro 10257 (CR4101818); La Union , Tres Rios , Zona Protectora de La Carpintera , 9°53'44.38"N, 83°58'31.79"W, 1400 m elev., 2014, Alvarenga and Canessa GA-00 (USJ109783, sequences ITSOQ845458, LSUOQ835182). San Jose , Desamparados , San Miguel , Jericó, Cerro Tablazo , ladera SO, Quercus sp. forest, 9°49'24.34"N, 84°2'26.56"W, 1880 m elev., on log, 30 Mar 2010, Carlos O. Morales s.n. ( USJ83642 ). Dota, San Gerardo, 9°33'0.86"N, 83°48'16.20"W, 2000-2300 m elev., 10 Jul 2000, R. Halling s.n. ( USJ 71604 ); 9°32'59.91"N, 83°48'18.26"W, 2300 m elev., 26 Nov 2010, J. Carranza JCV 128-10 (USJ104499); 9°33'1.13"N, 83°48'22.39"W, 2300 m elev., 10 Feb 2011, J. Carranza JCV 146-11 (USJ109500); 9°33'2.08"N, 83°48'26.31"W, 2200 m elev., 18 Sep 2022, M. Mardones GA-65 (USJ109784, sequences ITSOQ845461, LSUOQ835184); 9°33'3.85"N, 83°48'25.63"W, 2200 m elev., 18 Sep 2022, M. Mardones GA-63 (USJ109785, sequences ITSOQ845460, LSUOQ835183); Santa María, Jardín, 9°43'20.15"N, 83°58'28.91"W, 2200 m elev., 28 Oct 1979, J. Carranza JCV 90-79 ( USJ21299 ). León Cortés, San Pablo, Sector el casquillo, forest of Quercus spp., 9°41'37.98"N, 84°2'6.03"W, 2100 m elev., 22 Sep 2019, Beatriz Picado BPH16/GA-22 (USJ109794, sequences ITSOQ845459). Perez Zeledón, Siberia, 9°32'49.12"N, 83°42'48.29"W, 2900 m elev., on log, José Murillo 10 (USJ109055). San Marcos, Tarrazú, Canet, 9°41'38.92"N, 84°2'5.08"W, 2200 m elev., 22 Jan 2018, Beatriz Picado BPH21 (USJ109716) .

Discussion.

Ganoderma curtisii mainly differs from other Ganoderma species from Costa Rica by its lateral and long stipe, the colour of the stipe and pileus, the melanoid bands that originate from the stipe and run parallel to the upper surface of the context and the large basidiospores (11-17 × 8-10 µm). The Costa Rican specimens examined by us showed larger basidiospores than those reported by Murrill (1915, 9-11 × 5-8 µm), Torres-Torres and Guzmán-Dávalos (2005, 10.4-12.8 × 5.6-8 µm) and Loyd et al. (2018, 8.3-12.1 × 5.4-7.5 µm). Additionally, the cuticular cells in our specimens have a very strong amyloid reaction not mentioned by Torres-Torres and Guzmán-Dávalos (2005).

In Costa Rica, this species has been found in highlands and always associated with decaying wood in Quercus or Pinus forests. Torres-Torres and Guzmán-Dávalos (2012) reported it in Mexico occurring in the same type of forests. Ganoderma curtisii f. sp. meredithiae was recently erected to include those forms characterised by occurring exclusively on pines and showed slow cultural growth rate ( Loyd et al. 2018). Amongst the examined Costa Rican specimens, only one (GA-00) occurred in a pine forest; the other specimens were found in Quercus forests. Sequences from four specimens of G. curtisii from Costa Rica (GA-00, GA-22, GA-63 and GA-65) clustered in the same clade with G. lingzhi (clade II) with strong support (1/92), forming a terminal subclade with sequences labelled as G. curtisii and G. meredithae from the USA. This is the first report of the species in Central America and its distribution is probably strongly linked to the distribution of its host plants.

Figures

Figure 3. In-situ photos of basidiocarps of Ganoderma spp. in Costa Rica A G. amazonense (GA- 30) B G. applanatum (GA- 54) C G. australe (GA- 58) D G. cf. chocoense (GA- 03) E, F G. curtisii (JCV 128 - 10) G G. ecuadorense (MMG- 181) H G. oerstedii (Saenz 2049) I G. parvulum (GA- 09). Scale bars: 20 cm (A, H); 3 cm (B, C); 1 cm (D, E, I).

Figure 6. Ganoderma curtisii A, B basidiocarp (Navarro 10257) C context tissue (Navarro 10257) D cuticular cells (Navarro 10257) E, F basidiospores (Navarro 10132). Scale bars: 10 µm (D-F).