Ganoderma applanatum (Pers.) Pat., Hymenomyc . Eur. (Paris): 143 (1887)

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

3. Ganoderma applanatum (Pers.) Pat., Hymenomyc. Eur. (Paris): 143 (1887)

Fig. 3B

≡ Boletus applanatus Pers., Obs. Mycol. 2:2. 1799.

Description.

Basidiocarps perennial, sessile or with a contracted lateral base, dimidiate, woody, solitary, applanate to ungulate, irregular to tuberculate, 2-13 × 2-22 × 0.5-10 cm; pileus surface rugulose, glabrous, dull, greyish-brown to black, margin obtuse, zonate, whitish; context firm, reddish-brown, 10-50 mm thick, becoming dark with KOH; pore surface light brown to yellowish-brown, pores circular, 4-6 per mm; tube layers concolorous with context or yellowish-brown, up to 40 mm thick. Hyphal system dimitic or trimitic; contextual generative hyphae thin-walled, with clamps, hyaline, 2-4 µm diam.; skeletal hyphae thick-walled, yellowish-brown, aseptate, 2-4 µm diam., branched; binding hyphae thick-walled, branched, hyaline, 1-2 µm diam. Cuticular cells from the pileus: absent. Basidia not observed. Basidiospores ovoid, truncate; with two walls, yellow, negative in Melzer’s Reagent, 7-10 × 5-6 µm. Chlamydospores not observed.

Descriptions and illustrations.

Gilbertson and Ryvarden (1986), Ruiz-Boyer (1998).

Substrata.

Dead-standing hardwood trees or logs.

Altitudinal distribution.

Lowlands to highlands.

Geographic distribution.

Pantropical, common in tropical America.

Specimens examined.

Costa Rica. Alajuela: Los Chiles, Refugio Nacional de Vida Silvestre Cano Negro , 10°53'36.73"N, 84°47'45.49"W, 10 m elev., 07 Sep 1991, A. Ruiz-Boyer 13-91 ( USJ36357 ) . Guanacaste: Tilarán, 10°27'13.66"N, 84°58'13.61"W, 534 m elev., 10 Oct 1980, J. A. Saénz & J. Carranza 314-80 ( USJ21274 ) . Heredia: Bosque de La Hoja , 10°3'44.38"N, 84°5'43.09"W, 1496 m elev., 05 Mar 1986, J. Carranza JCV 67-86 ( USJ22291 ) . San José: Dota, San Gerardo , 9°33'1.63"N, 83°48'9.66"W, 2000-2300 m elev., 18 Sep 2022, M. Mardones GA-64 (USJ109782, sequences ITSOQ845455, LSUOQ835179); El Empalme, Ojo de agua, 2250 m elev., 28 Oct 1979, J. Carranza JCV 131-79 ( USJ21297 ) .

Discussion.

As mentioned above, the species G. applanatum is morphologically similar to G. australe , but the shorter basidiospores and the absence of resinous deposits or melanoid substances in the context of G. applanatum can distinguish them. According to Ryvarden (2004), G. applanatum is a species restricted to temperate zones and, according to Fryssouli et al. (2020), it has a Holarctic distribution. However, our results show the presence of this species or a species closely related to G. applanatum , in Costa Rica. The sequence from the GA-64 specimen clusters, as an independent lineage, with several sequences identified as G. applanatum from Europe and Asia in a strongly-supported terminal clade (1/78) within clade III. This result would be the first record of this species in the Tropics confirmed by molecular data. Therefore, considering the morphological examination and the phylogenetic position of the sequence, we have decided to identify this specimen as G. applanatum . Increasing the number of collections and molecular data is essential to determine if the species observed in Costa Rica is G. applanatum or a closely-related species.

While examining the G. applanatum specimens from Costa Rica, we found four specimens with smooth basidiospores, which agree with the description of G. applanatum var. laevisporum C.J. Humphrey & Leus-Palo. For details on these specimens, see the Excluded Species section below.

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).