Tuber melanosporum Vittad.

Leonardi, Marco, Iotti, Mirco, Mello, Antonietta, Vizzini, Alfredo, Paz-Conde, Aurelia, Trappe, James & Pacioni, Giovanni, 2021, Typification of the four most investigated and valuable truffles: Tuber aestivum Vittad., T. borchii Vittad., T. magnatum Picco and T. melanosporum Vittad., Cryptogamie, Mycologie 20 (9), pp. 149-170 : 161-162

Tuber melanosporum Vittad.

( Figs 2D ; 3G, H ; Appendix 2 )

Monographia Tuberacearum: 36 (1831).

Tuber nigrum Bull., Herbier de la France 8: t.356 (1788). (MB 204568).

MYCOBANK NUMBER. — MB 192144.

GENBANK. — MZ423176 (nrITS), MZ458420 (nr β- tubulin), MZ458424 (nrEF 1-α).

LECTOTYPE OF TUBER MELANOSPORUM VITTAD. — Vittadini 1831: tab. II fig. III; here reprinted in Fig. 3 . (here designated; MycoBank Typification number: MBT 10001899 ):

EPITYPE OF TUBER MELANOSPORUM VITTAD. — Italy. Lombardy, Monza, Parco Villa Reale, 1.II.2019, sub Carpinus betulus and Tilia cordata , 45°35’39”N, 9°16’25”E, six ascomata, legit Stefano Seghezzi, det. Giovanni Pacioni (epi-, AQUI[AQUI 10152] here designated; MycoBank Typification number: MBT 10001900).

Authentic Vittadini specimens examined: K(M) 254905, 254904 e 254904, TO e UPS (F‒628213).

DESCRIPTION

Ascomata

Hypogeous, globose or irregular, sometimes lobed, rarely more than 10 cm broad, surface of peridium reddish brown then reddish black or brownish black (#330000 very dark red), covered with pyramidal warts 2-5 mm at the base and 0.5-2.5 mm tall, depressed at the apex and with 4-6 sides joined with radial edges.

Gleba

Firm and compact, from reddish-gray to black-purple or black with violet hues (3B2512-3B3938 dark shade orange to 26211D-2B2017 very dark orange shade); sterile veins thin, much branched, whitish or reddish when exposed to the air.

Odor

Intense, complex, pleasant, the taste with a bitter aftertaste.

Peridium

300-450 Μm thick; exoperidium pseudoparenchymatous, 70-15 Μm thick, the outer layer 40-80 Μm thick, of globose to sub-globose sclerenchymatous pigmented cells, with very thickened walls and the cellular lumen reduced or absent, 12-20 × 7-12 Μm, limited to the superficial part of the warts underlaid by a palisade layer 33-65 Μm thick of elongated cells (16-26 × 5-6.5 Μm) with the major axis perpendicular to the surface just below the exoperidium; endoperidium 240-350 Μm thick, pale with a pseudoparenchymatous mixture of cells 4-11 × 2-7 Μm and ranging from subglobose, cuboid, polygonal, cylindric or irregularly swollen, elongated at one end, pale with collenchymatic walls 2-3 Μm thick. The palisade structure is not always visible, depending on the cut, generally within the outermost layer of sclerenchymatous cells lies a homogeneous pseudoparenchymatous layer of endoperidium.

Asci

Globose to subglobose, 90-145 × 70-125 Μm, with walls up to 4 Μm, sometimes thicker in the final stages VI of ripening ( Zarivi et al. 2014), short stalked or thick, sessile with a crozier at the base; containing 1-6 spores.

Ascospores

Spiny, ellipsoid, Q 1.28-1.56, 20-56 × 14-36 Μm excluding ornamentation, inversely proportional in size to the number of spores in the ascus, opaque when ripe, intense brown, blackish, with black-dark brownish spines, short, robust and rigid, sometimes curved, 1.5-3.0 (-4) Μm long to 2 Μm wide at the base, usually separated but sometimes connected at the base to form short crests, occurring at a density of 11-13 spines per 100 Μm 2.

Gleba

Hyphae hyaline, 14-36 × 6-8 Μm, at full maturity brownish.

HABITAT. — mainly under broadleaf trees and shrubs, especially thermophilic oaks, but also European hop-hornbeam ( Ostrya carpinifolia ) and hazelnuts ( Corylus avellana ), rare under pines or other conifers. Its natural environments are extended in calcareous soils in southern Europe from the Iberian Peninsula to France and Italy, rarer in the Balkans and western Anatolia, late autumn and winter ( Le Tacon 2017).

Figures

FIG. 2. — Table I (XX),lectotype ofTuber borchii Vittad.(red arrowed).

FIG. 3. — Table II, lectotypes of Tuber melanosporum Vittad.(red arrowed) and Tuber aestivum Vittad.(black arrowed).

APPENDIX 2. — Tuber melanosporum Vittad.epitype:different cut of peridium structure × 40. Scale bar:50 µm.