Calostoma tooteic Deloya-Olvera, Virgen-Vasquez, Xoconostle-Cázares & J. Pérez-Moreno, 2023

Deloya-Olvera, Miriam, Xoconostle-Cazares, Beatriz, Vasquez, Sofía Virgen, Pérez-Moreno, Jesús, Martínez-González, César Ramiro, J. Almaraz, Juan, Jimenez, Mario & Sánchez-García, Martín E., 2023, Two new neotropical species of the ectomycorrhizal gasteroid genus Calostoma (Sclerodermatineae, Boletales) used as a food source by the Ayuuk jä’äy ethnic group from Southern Mexico, Phytotaxa 612 (2), pp. 148-158 : 154

Calostoma tooteic Deloya-Olvera, Virgen-Vasquez, Xoconostle-Cázares & J. Pérez-Moreno sp. nov.

Index fungorum number: IF556487, Mycobank number: MB 830882, GenBank MF521437 and MF521439

Etymology:— Refers to the name used by Ayuuk jä’äy people to designate the long stipe of this edible species, and the possibility to find this fungus in the rainy season; too teic (too = rain, teic =foot) literally meaning “the rain foot”.

Gasterocarp formed by a tall stipe with a globose spore-sac at the apex; stipe is formed by longitudinal anastomosed strands and is transparent reddish brown, cartilaginous when fresh and hard when dry, from 1.5 to 5 cm in height, × 1.8 to 2.20 cm in diameter. Spore-sac, globose, orange to red, 20–28 mm in diameter, initially covered by a thin gelatinous exoperidium containing small reddish “seeds” that fall embedded in the gelatine around the spore-sac, sliding down the stipe and leaving the pore-sac completely bare; ostiole apical, with five to six raised edges; basidiospores ellipsoid (11.3–) 12.2–18.0 (–19.2) × (8.5–) 8.8–12.4 (12.8) µm, Q= 1.11–1.81 μm; Qm=1.4 μm, ornamented with a reticulum (exospore) with internal and external layers ( Figure 2f ). Spore sac formed by a network of hyphae from 2.2 to 5.8 μm that degrades ( Figure 2c–e ).

Holotype:— MEXICO, Oaxaca, Santa Maria Tlahuitoltepec , on Quercus obtusata forest soil, 17°6’41.6”N, 96°3’33.7”W, 2327 m, 19 August 2015, Deloya-Olvera 57 ( MEXU29002 !, holotype designated here).

Paratype — MEXICO, Oaxaca, Santa Maria Tlahuitoltepec , on Quercus obtusata forest soil, 17°6’59.7”N, 96°3’23.2”W, 2477 m, 20 August 2015, Deloya-Olvera 58 ( MEXU29009 !, paratype designated here) .

Diagnosis: differing from other Calostoma species by exoperidium gelatinous, thin and ephemeral with age; size of spores: (11.3–)12.2–18.0(–19.2) × (8.5–)8.8–12.4(–12.8) µm, Q= 1.11–1.81 μm Qm=1.4 μm and stipe 1.5–5.0 cm high × 1.5–2.0 cm in diameter.

Notes: Calostoma tooteic differs from its closest phylogenetic species C. cinnabarinum due to: i) its greater globose spore-sac; the former species has a 20–28 mm spore-sac in diameter, while as pointed out above in the case of C. cinnabarinum smaller measures have been recorded: 10–20 mm; 10–15 mm; 8–10 mm and 8–12 mm by Masse (1888); Castro-Mendoza et al. (1983); Kim et al. (2007) and Baseia et al. (2010), respectively; ii) the narrower spores reported for C. cinnabarinum : 8–10 µm, 6.3–8.5 µm, 6.5–8.5 µm, 5–8 µm, 8–10 µm and 7.5–9 µm, by Masse (1888); Coker & Couch (1928); Castro-Mendoza et al. (1983); Kim et al. (2007) and Guzmán (1973), respectively, while our specimens have spores ranging from 8.8–12.4 µm in width; and iv) as mentioned for C. naaxtutus , there were robust genetic differences which showed that C. tooteic is included in a monophyletic clade (1 Bayesian Posterior Probability and 100% bootstrap proportion for Maximum likelihood), closer but different to that of C. cinnabarinum . Similarly than in the case of. C. naaxtutus , C. tooteic differs from the other two species of the genus previously recorded from Mexico, because C. lutescens has globose spores, (6–)7.7–10.5 µm in diameter; and C. ravenelii has a non-gelatinous exoperidium ( Guzmán, 1973).

Figures

FIGURE 2. Calostoma naaxtututs (a–b) and C. tooteic (c–f). a. Gasterocarp appearance (Holotype), showing color variation (in the top right corner). b) Scanning electronic microphotography showing the ornamentation pattern of spores; c–d) Gasterocarp appearance (Holotype), showing colour variation in (e). f. Scanning electronic microphotography showing the ornamentation pattern of spores; (g) Gathering of Calostoma ethnotaxa by Ayuuk jä´äy women.