Tuber itzcuinzapotl de la Fuente & Rosales-Rosales, 2024

Fuente, Javier Isaac De La, Rosales-Rosales, Wendy, Martínez-González, César Ramiro, Martínez-Reyes, Magdalena, Elizondo-Salas, Andrea Carolina & Pérez-Moreno, Jesús, 2024, Tuber itzcuinzapotl sp. nov. (Tuberaceae, Pezizomycetes), the first edible truffle reported from Mexico with traditional biocultural importance, Phytotaxa 635 (3), pp. 206-216 : 210-211

Tuber itzcuinzapotl de la Fuente & Rosales-Rosales , sp. nov.

Mycobank number: MB 84987, GenBank: OR429351 and OR429351

Etymology: —Refers to the name used by the Nahua people to designate this edibles species itzcuinzapotl (itzcuin =dog, and zapotl =zapote, a native sweet fruit).

Ascomata 35 × 28 mm, subglobose irregular to lobate, pale brown, darkening when touched, finely verrucose or granulose, 5−7 verrucae per mm, dry texture, without rhizomorphs at the base. Peridium thinner than 1 mm in width, grey, brown, yellowish when dry. Gleba marbled, pale brown to greyish brown, dark brown when mature, with abundant white veins, some coalescing in the peridium. Taste and smell fruity. Peridium 200−400 µm composed of two layers: Epicutis 180−250 µm, composed of a pseudparenchymatous layer composed of hyaline, inamyloid, thin-walled, 5−20 µm subglobose to globose hyphae in diameter, with thick, brownish cell-walls, usually forming pyramid-like structures of 150−200 × 60−180 µm, with scarce erect clavate hyphae of 11−30 × 6−10. Subcutis 80-150 µm width, composed of strongly interwoven hyphae, prosenchymatous in some areas, 4−12 µm in diameter, tubulose, rarely subglobose, and occasionally inflated near the septa, hyaline, inamyloid, thin-walled. Veins composed of strongly interwoven hyphae, 2−16 µm in diameter, hyaline, tubulose to inflate near the septa, hyaline, thin-walled, like those from the subcutis. Asci 34−70 × 20−50 µm, globose to subglobose, hyaline, some with a globose pedicel reaching up to 10 µm, mostly 2-spored, monosporic, rarely 3 or 4-spored, thick-walled (4 µm in diameter). Ascospores ellipsoid, pale brown to light brown, with angular alveoli of (2)5−10 × 3−5(7) µm, 5−8 sides, projecting up to 6 µm, thick-walled (up to 3 µm); 1-spored asci have ascospores of 40−52 × 23−30 µm; 2-spored asci have ascospores of 27−34 × 15−22 µm, 3-spored asci have ascospores of 22−39 × 15−19 and 4-spored asci have ascospores of 25−42 × 13−30 µm.

Holotype: — MEXICO. Veracruz: Soledad Atzompa municipality, Mexcala town , 18° 41’ 46’’ N, 97° 10’ 00’’ W, 2400 m, 17 April 2023, Wendy Rosales-Rosales, (52-ZON, holotype designated here).

Habitat, habit, distribution: —Solitary. So far, it is only known from the type locality, growing under P. patula .

Diagnosis: —The new species differs from other species within the Maculatum clade by its pale brown ascomata, finely granular peridium, composed of subglobose hyphae, forming pyramid-like structures, clavate terminal cells of 11−30 × 6−10 µm, pale brown to gray gleba, and 22−52 × 15−40 µm alveolate ascospores.