Introduction
The genus Fuscoporia was described by Murrill (1907) with the type species F. ferruginosa (Schrad.) Murrill. This genus belongs to the family Hymenochaetaceae, order Polyporales, class Agaricomycetes of the phylum Basidiomycota. It is characterized by the formation of annual or perennial basidiomata, resupinate or pileate, monomitic or dimitic hyphal system, abundant hymenial setae, generative hyphae with encrusted crystals and hyaline basidiospores, that are allantoid, subglobose, ovoid, ellipsoid, subcylindrical to cylindrical, thin and smooth walled; it has a cosmopolitan distribution (Wagner and Fischer, 2001; Groposo et al., 2007; Baltazar et al., 2009; Baltazar and Gibertoni, 2010; Raymundo et al., 2013a, b; Chen and Yuan, 2017; Chen et al., 2019, 2020). Fifty species belonging to this genus have been described in the world according to Chen et al. (2020). In Mexico, 16 species have been cited (Index Fungorum, 2021): F. callimorpha (Lév) Groposo, Log.-Leite & Góes-Neto, F. contigua (Pers.) G. Cunn., F. chrysea (Lév.) Baltazar & Gibertoni, F. contiguiformis (Pilát) Raymundo, R. Valenz. & Esqueda, F. coronadensis (Rizzo, Gieser & Burds.) Raymundo, R. Valenz. & Cifuentes, F. ferrea (Pers.) G. Cunn., F. ferruginosa, F. gilva (Schwein.) T. Wagner & M. Fisch., F. latispora Y.C. Dai, Q. Chen & J. Vlasák, F. mesophila Raymundo, R. Valenz. & Pacheco, F. nicaraguensis Murrill, F. palmicola (Berk. & M.A. Curtis) Bondartseva & S. Herrera, F. rhabarbarina (Berk.) Groposo, Log.-Leite & Góes-Neto, F. viticola (Schwein.) Murrill, F. wahlbergii (Fr.) T. Wagner & M. Fisch., F. xerophila Raymundo, R. Valenz. & Esqueda. The objective of this work is to describe and illustrate Fuscoporia valenzuelae, a new species from the tropical dry forests in Mexico.
Materials and Methods
The Chamela-Cuixmala Biosphere Reserve was surveyed during two sampling trips in September 2010 and 2011, in the locality Búho (19°29'58.39"N, 105°02'37.97"W, 124 m a.s.l.). The Sierra de Álamos-Río Cuchujaqui Biosphere Reserve was surveyed during two collection trips in October 2013 and 2014, in the locality Rancho La Sierrita (26°58'25"N, 108°56'42"W, 528 m a.s.l.) (Fig. 1). The collected specimens were described from fresh material, processed and deposited in the herbarium ENCB, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico. The species were determined by observing transversal and longitudinal sections of the basidiomata in temporary preparations mounted in 70% alcohol, 10% KOH, and colors coded according to Kornerup and Wanscher (1978). Morphological examinations were conducted using protocols outlined by Raymundo et al. (2013a,b) and Ryvarden (2004). Anatomical characteristics were measured from rehydrated tissues in 5% aqueous KOH and Melzer’s reagent. Line drawings were made to scale using an optical light microscopy (K-7 Zeiss, Jena, Germany) with clear camera, and macroscopic photographs were taken with a Nikon Coolpix 4300. The meaning of all terms is based on Ulloa and Hanlin (2012).
Results
We here present a dichotomous identification key of the Mexican Fuscoporia species modified from Raymundo et al. (2013a,b).
Key to Fuscoporia species in Mexico
1a. Hyphal setae present in trama, margin, and/or subiculum … 2
1b. Hyphal setae absent … 6
2a. Basidiospores globose to subglobose, basidiomata resupinate … 3
2b. Basidiospores ellipsoid, broadly ellipsoid, oblong to cylindrical, basidiomata resupinate to pileate … 4
3a. Pores 7-9 per mm, hymenial setae 24-36 μm × 6.4-9.2 μm, subulate, straight and hyphal setae on the sterile margin 60-136 μm × 6-12 μm, basidiospores 2.4-4.4 μm, globose … F. nicaraguensis Murrill
3b. Pores 4-5 per mm, hymenial setae 48-52 μm × 6.4-8 μm, ventricose to ventricose-rostrate, straight; hyphal setae on the margin or subiculum 88-180 μm × 12-20 μm, straight, lanceolate to lageniform; basidiospores 5.12-5.46 μm × 4-4.48 μm, subglobose …. F. xerophila Raymundo, R. Valenz. & Esqueda
4a. Pores 1-5 per mm … 5
4b. Pores 7-9 per mm, hymenial setae 30-60 μm × 6-10 μm, subulate, straight and hyphal setae on the sterile margin 90-150 μm × 6-10 μm, basidiospores 5-7 μm × 2.4-3.5 μm, cylindrical … F. ferruginosa (Schrad.) Murrill
5a. Basidiospores ellipsoid; hymenial setae (40 μm; hyphal setae up to 80 μm; pores 1-2 per mm, growing on Astronium graveolens Jacq. …. F. valenzuelae Raymundo
5b. Basidiospores oblong to subcylindrical; hymenial setae (40 μm; hyphal setae up to 80 μm; pores 2-5 per mm; growing on several hosts …. 6
6a. Hymenial setae 40-60 μm × 6-8 μm, subulate, straight, tramal setae 50-90 μm × 5-12 μm, subulate, straight and hyphal setae on the floccose margin up to 120 μm long, basidiospores 5-7 μm × 2.4-3.5 μm, subcylindrical to oblong … F. contigua (Pers.) G. Cunn.
6b. Hymenial setae 55-72 μm × 6-9 μm, straight, tramal setae absent, straight and hyphal setae on the tomentose margin up to 110 μm long, basidiospores 4-5 μm × 2.8-3.5 μm, oblong ... F. latispora Y.C. Dai, Q. Chen & J. Vlasák
7a. Basidiomata resupinate to effused-reflexed … 8
7b. Basidiomata pileate-sessile … 11
8a. Pores 1-3 per mm … 9
8b. Pores 4-6 per mm …. 10
9a. Basidiospores oblong to cylindrical, 4-5 μm × 2-2.5 μm, pores angular, sinuous to labyrinthiform, hymenial setae 32-64 μm × 6.4-7.2 μm, subulate … F. palmicola (Berk. & M.A. Curtis) Bondartseva & S. Herrera
9b. Basidiospores cylindrical to slightly curved, 7-8 μm × 1.6-2 μm, pores angular, hymenial setae 50-70 μm × 5-7 μm, subulate … F. contiguiformis (Pilát) Raymundo, R. Valenz. & Esqueda
10a. Basidiospores broadly ellipsoid to subglobose, 3.2-4 μm × 2.4-3 μm, hymenial setae 30-50 μm ×5-8 μm, ventricose to subulate ... F. chrysea (Lév.) Baltazar & Gibertoni
10b. Basidiospores cylindrical, 5.5-7.6 μm × 2.4-3.2 μm, hymenial setae 27-37 μm × 5-7 μm, subulate … F. ferrea (Pers.) G. Cunn.
11a. Basidiospores cylindrical to slightly curved, 7-9 μm × 1.5-2 μm, hymenial setae 25-75 μm × 5-8 μm, subulate .. F. viticola (Schwein.) Murrill
11b. Basidiospores globose to subcylindrical, never curved, >2 μm in diameter … 12
12a. Hymenial setae hooked, some straight, 25-44 μm × 8-13.2 μm, basidiospores subglobose to ellipsoid, basidiomata applanate, dimidiate to broadly attached, pores 6-8 per mm, circular to elongate … F. wahlbergii (Fr.) T. Wagner & M. Fisch.
12b. Hymenial setae straight ... 13
13a. Basidiomata large, 100-350 mm × 150-300 mm × 25-100 mm, applanate, dimidiate to broadly attached, pores (5-)6-7(-8) per mm, circular, hymenial setae 20-32 μm × 6.4-9 μm, ventricose to subulate, basidiospores 3.2-5.6(-6) μm × 3.2-4 μm, subglobose to ovoid, growing only on conifers ... F. coronadensis (Rizzo, Gieser & Burds.) Raymundo, R. Valenz. & Cifuentes
13b. Basidiomata small to medium size, growing only on angiosperms … 14
14a. Pileus surface with a distinctive black crust, glabrous and sulcate, pores 6-9 per mm, hymenial setae 20-30 μm × 4.8-7.2 μm, subulate, basidiospores 3.2-4 μm × 2-3 μm, ellipsoid … F. rhabarbarina (Berk.) Groposo, Log.-Leite & Góes-Neto
14b. Pileus surface without a distinctive black crust ... 15
15a. Basidiomata triquetrous to ungulate, pileus surface velutinate to tomentose, concentrically sulcate, pores 6-8 per mm, circular, hymenial setae 28-40 μm × 8.8-16 μm, ventricose, basidiospores 4.0 μm × 3.2-3.8 μm, subglobose to ovoid … F. mesophila Raymundo, R. Valenz. & Pacheco
15b. Basidiomata applanate to convex, hymenial setae <10 μm broad … 16
16a. Hymenial setae 16-28 μm × 6-8.8 μm, subulate to ventricose, basidiospores 3.6-4.8 μm × 2-3 μm, oblong to subcylindrical ... F. callimorpha (Lév) Groposo, Log.-Leite & Góes-Neto
16b. Hymenial setae 20-40 μm × 6-10.2 μm, ventricose to subulate, basidiospores 4-5 μm × 2.5-3 μm, narrowly ellipsoid to oblong … F. gilva (Schwein.) T. Wagner & M. Fisch.
Hymenochaetaceae
Fuscoporia valenzuelae Raymundo, sp. nov. Figs. 2,3,4,5.
TYPE: MEXICO. Jalisco, municipality La Huerta, Reserva de la Biosfera Chamela-Cuixmala, Búho, 124 m, 19°29'58.39"N, 105°02'37.97"W, 27.IX.2010, T. Raymundo 3475 (holotype: ENCB); Mycobank: MB839199.
Fuscoporia valenzuelae differs from Fuscoporia contigua by its smaller pores, its shorter and ellipsoid basidiospores and its hymenial setae and hyphal setae of small size. It lacks tramal setae and grows on Astronium graveolens in tropical dry forest.
Basidiomata annual, 100-150 × 20-40 × 0.1-0.3 cm, resupinate, adnate, becoming widely effused, corky to woody, easily separable of the substrate; margin sterile, golden brown (5A3), yellowish brown (5A4), matted; hymenophore poroid, honey (6D7) to red brown (6E6), cracked with age in dry specimens, grayish brown (6D5) to golden brown (6D6) in old specimens; pores angular to irregular, 1-2 per mm, 200-400 × 160-180 μm; dissepiments thin to thick and lacerated, 50-100 μm thick; tubes 1 mm deep, one layer, tough to woody, grayish brown (6E3) to brown (5E8); context or subiculum very thin, 1-3 mm thick, pale yellow (5A3); hyphal system dimitic, generative hyphae simple septa, hyaline to pale yellow in KOH, thin-walled, 2-3.4 µm diameter; skeletal hyphae yellowish brown to reddish brown, unbranched or rarely branched, thick-walled, 3.2-4.8 m diameter; hymenophoral trama 50-60 μm thick, composed by interwoven hyphae, generative hyphae hyaline to pale yellow in KOH, thin-walled, simple to slightly branched, 2.4-3.2 μm diameter, hyphae projecting beyond the hymenia and on the edge of dissepiments strongly encrusted with crystals; skeletal hyphae yellowish brown to reddish brown in KOH, unbranched, thick-walled, 3.2-4 μm diameter; contextual trama with interwoven hyphae, generative hyphae rare, hyaline to pale yellow in KOH, simple to scarcely branched, thick-walled, 1.6-2.4 μm diameter; skeletal hyphae dominant, reddish brown in KOH, unbranched, thick-walled, 2.4-4.8 μm diameter; hyphal setae 64-80 × 6-14 μm, straight, lanceolate to lageniform, acute, dark brown in KOH, thick-walled, only found in subiculum and margin; hymenial setae 33-40 × 6-9 μm, ventricose to subulate, acute, reddish brown to dark brown in KOH, thick-walled; cystidioles hyaline, lageniform; basidia not observed; basidiospores 4.5-5 μm × 3-3.5 μm, ellipsoid, hyaline, thin-walled, smooth and with guttation.
Habit and habitat: growing on living trees of Astronium graveolens (Anacardiaceae), causing white rot, in tropical dry forest, at 40-220 m a.s.l.
Etymology: the epithet honors Dr. Ricardo Valenzuela, specialist in the family Hymenochaetaceae.
Additional material examined: MEXICO. Jalisco, municipality La Huerta, Chamela-Cuixmala Biosphere Reserve, Búho, 124 m, 19°29'58.39"N, 105°02'37.97"W, 17.IX.2011, T. Raymundo 3996 (ENCB). Sonora, municipality Álamos, Sierra Álamos-Río Cuchujaqui Biosphere Reserve, La Sierrita, 528 m, 26°58'25"N, 108°56'42"W, 16.X.2013. T. Raymundo 4873 (ENCB); loc. cit., 8.X.2014. T. Raymundo 5473 (ENCB).
Taxonomic notes: this species is characterized by resupinate, very long basidiomata, up to 150 cm long, growing on living trees, pores 1-2 per mm; hyphal and hymenial setae present, basidiospores ellipsoid. Fuscoporia contigua resembles this species, with resupinate basidiomata; however, these are 5-10 cm long with 2-3 pores per mm. Moreover, it differs by hymenial setae of 40-60 × 6-8 μm, hyphal setae of 80-120 × 6-12 μm and it produces basidiospores that are oblong-ellipsoid (5-7 × 2.4-3.5 µm). This species develop tramal setae of up to 90 µm long. Fuscoporia ferruginosa differs by the presence of more pores per mm (7-9) and cylindrical spores; F. chrysea can be distinguished by the golden yellow margin of basidiomata and ellipsoid spores.
Conclusions
The genus Fuscoporia with 17 species is the best represented taxa of Hymenochaetaceae in Mexico, which is the country with the highest number of registered species. One of the species with the greatest morphological variability has been F. contigua which was considered a complex by Chen et al. (2019). However, they indicated that this species has a wide distribution in the northern hemisphere, and demonstrated that various specimens from China, Costa Rica, Mexico, and the United States of America turned out to be new species. From this study, Fuscoporia latispora was described for Mexico from the state of Veracruz. Therefore, it is very likely that various specimens from the Neotropical region that are found under the epithet of F. contigua will have to be reviewed in detail. In this case, F. valenzuelae is a species that is distributed in the tropical dry forest of the Mexican Pacific Coast Plain which will probably be linked to the distribution of its host.