Elaphomyces castilloi J. Garcia , Guevara & de la Fuente, 2023

de la Fuente, Javier Isaac, Garcia-Jimenez, Jesus, Raymundo, Tania, Sanchez-Flores, Marcos, Valenzuela, Ricardo, Guevara-Guerrero, Gonzalo, Perez-Ovando, Erika Cecilia & Martinez-Gonzalez, Cesar Ramiro, 2023, Elaphomyces castilloi (Elaphomycetaceae, Ascomycota) and Entoloma secotioides (Entolomataceae, Basidiomycota), two new sequestrate fungi from tropical montane cloud forest from south Mexico, MycoKeys 96, pp. 127-142 : 127

Elaphomyces castilloi J. Garcia, Guevara & de la Fuente sp. nov.

. Fig. 4A-G

Type material.

Holotype. Mexico. Chiapas: la Trinitaria Municipality, Lagunas de Monte bello, alt. 1004 m, 16°53'N, 93°27'W, 16 August 2019, J. García 18640 (Holotype-ITCV).

Diagnosis.

Elaphomyces castilloi differs from other species of the genus by the following combination of characteristics: ascomata embedded in a yellow mycelial mat, dull blue powdery gleba, and globose reticulate ascospores (9.7-11.5 µm).

Etymology.

The species was named Elaphomyces castilloi in honor of José Castillo Tovar (ad memoriam), a Mexican pioneer mycologist dedicated to studying the fungi from northeast Mexico.

Description.

Ascomata globose to ellipsoid, 14-32 mm, embedded in a thick, yellowish orange (4A7) to deep yellow (4A8), with a membranous mycelial mat, occasionally incorporating soil particles, and debris, loose but compacted near the peridium, easily detachable. Peridium surface black, slightly rough, carbonaceous, inner peridium grayish brown (8D3), sometimes with white mycelial strand, near the gleba forming a discontinuous layer. Gleba powdery, dull blue (23D5), compacted when young, becoming loose when mature, with scattered grey hyphae (25C1); odor and taste fungoid.

Mycelial mat hyphae cylindrical, 2-6 µm diameter, septate, hyaline, thin-walled, loosely arranged. Epicutis: 125-200 µm diameter, composed of compacted hyphae, 3-8 µm diameter, strongly interwoven, subglobose to irregular, black in 5% KOH, thick-walled. Subcutis 500-650 µm diameter, composed by prostrated and compacted hyphae, 8-15 µm in diameter, hyaline to dull grey in 5% KOH (25D4), becoming irregular near the gleba, thin-walled. Asci subglobose, 32-38 × 25.8-30.1 µm, 5 to 8-spored, hyaline, thin-walled. Ascospores 9.7-11.5 µm (n = 30), globose, rarely subglobose, reticulated, projecting up to 1.9-2.7 µm, forming small bridges (less than 2 µm), with obtuse tips, golden brown color (5D7), thick-walled.

Additional material examined.

Mexico. Chiapas: la Trinitaria Municipality, Lagunas de Monte bello, alt. 1004 m, 16°53'N, 93°27'W, 16 August 2011, Guevara 1102 (Paratype-ITCV). ITS: OP821419 , LSU: OP824739 .

Distribution.

Known only from the Mexican state of Chiapas, growing scattered, and hypogeous under Quercus sp. in montane cloud forest.

Notes.

Elaphomyces castilloi is phylogenetically close to Elaphomyces aculeatus Vittad. from Italy, the last one with similar ascospore color and ornamentation. It was previously reported from Mexico by Gómez-Reyes et al. (2012). Elaphomyces aculeatus has a reddish peridium and dark-brown gleba; meanwhile, E. castilloi has dark peridium and bluish gleba. The yellow mycelial mat and the small ascospores resemble those of Elaphomyces citrinus Vittad. (Section Elaphomyces citrinus Malacodermei ). However, it differs by the smaller ascocarp (less than 10 mm), the brownish peridium in young specimens, and by its geographic distribution (Europe) ( Pegler et al. 1993). Although the morphological features of the new species are typical in the Malacodermei , these are also seldom observed in the Ceratogaster ( Paz et al. 2017).

Figures

Figure 4. Elaphomyces castilloi (Holotype) A ascomata B mycelial mat hyphae C subcutis D asci E, F ascospores in KOH G detail of ascospore ornamentation in SEM.