Elaphomyces readii Pérez-Moreno & de la Fuente, 2023

Fuente, Javier Isaac De La, Pérez-Moreno, Jesús, Martínez-Reyes, Magdalena, Ayala-Vásquez, Olivia, Martínez-González, César Ramiro & Aguirre-Acosta, Celia Elvira, 2023, Elaphomyces readii (Elaphomycetaceae, Eurotiomycetes), a new medicinal species of hypogeous fungus with biocultural importance from Mexico, Phytotaxa 594 (4), pp. 241-250 : 245-247

Elaphomyces readii Pérez-Moreno & de la Fuente , sp. nov. ( Fig. 2 ).

Mycobank no. 846810

Diagnosis: — Elaphomyces readii is mainly characterized by the peridium yellowish to reddish brown in the outer part, then whitish, with yellowish to reddish brown hues in the proximity to the gleba and ascospores ranging 20–57 µm in diameter, ornamented with small flat papillae, sometimes coalescing forming a subreticulum The macro- and micromorphological characteristics in conjunction with the nrITS-based phylogenetic analysis support the proposal of this new species.

Holotype: — MEXICO. Oaxaca: Tlaxiaco City, state of Oaxaca, purchased in a traditional market , 17° 07’ 17. 21’’ N, 97° 34’ 97. 50’’ W, 2040 m a.s.l., 17 July 2016, Pérez-Moreno J. ( 2501-ITCV , holotype).

Etymology: —This species is dedicated, as “ readii ”, in honor to Professor Sir David J. Read, eminent mycologist, Emeritus Professor of the University of Sheffield, England, Secretary of the Royal Society (London) and a giant scientist in the study of the mycorrhizal symbioses (like the giant spores of the new species, averaging 52.33 µm in diameter), with more than 55 years of experience contributing to the understanding of the ecophysiology of mycorrhizal symbioses, and was knighted in 2007 by the Queen of England for his outstanding scientific contributions.

Description: — Ascomata 20–45 mm, globose to sub globose, slightly flattened when mature, sometimes lobulate, yellowish to reddish brown (5F4–5E4), dry, finely ornamented with flat papillae, crowded (2–3 papillae per mm), without mycelial strands. Peridium up to 1 to 1.5 mm thick, yellowish in the outer part, then whitish, yellowish to reddish brown near the gleba, firm, hard when dried, sometimes bruising reddish or orange when cut. Gleba pulverulent, white, then purple (18F8), dark purple (18F6) to blackish when mature, with some pale fibrils radially arranged, odor and taste fungoid. Peridium composed of three layers. Exoperidium 100–230 µm thick, composed of prostrate and horizontally arranged hyphae, 4–7 µm in diameter, hyaline or with golden content, septate, thin-walled, forming irregular pyramids of 400–650 µm. Mesoperidium 800–1200 µm thick, composed of interwoven tubulous hyphae, compacted, 3-5 µm in diameter, thin-walled. Endoperidium 250–450 µm thick, similar in structure to the mesoperidium, with tubulous interwoven hyphae, 5–15 µm in diameter, thick-walled, some with yellowish to reddish brown incrustations in the cell walls. Asci 45–62 × 38–42 µm, ellipsoid, rarely globose, hyaline, 6–8 spored, some with a pedicel up to 7 µm long, thick walled. Ascospores 20–57 µm (Average=52.33 µm, n=50), globose, with slender spines, crowded, reaching 3-5 µm long, sometimes converging in small ridges, forming a sub-reticulum or alveoli up to 5 µm in diameter, brown in 3% KOH, some with a big guttula, thick-walled.

Habitat, habit, distribution: —Solitary to disperse. So far only known from the type community in Tlaxiaco municipality, growing under Pinus spp. from the beginning of July to the end of August, having a short distribution in the middle of the rainy season phenology.

Specimens examined: — MEXICO. Oaxaca: Tlaxiaco Municipality, purchased in a traditional market , 17° 07’ 17. 21’’ N, 97° 34’ 97. 50’’ W, 2040 m, 20 August 2016, Pérez-Moreno J. ( 2501, 2502, 2503, 2504, 2505 ITCV) .

Figures

FIGURE 2. Elaphomyces readii. A. Fresh ascomata in different stages (Holotype). B. Large collection from one market seller. C. Mixtec woman selling fresh ascomata (right) and red corals from the Pacific Ocean (left) with medicinal purposes in a Mexican traditional market. D. Exoperidium. E. Mesoperidium. F. Endoperidium. G. Mature ascospores. H. Asci. I. Detail of the ascospore ornamentation under SEM. Scale bars: A and B= 20 mm; D= 20 µm; E-H=10 µm.