TUBER MESENTERICUM Vittadini
Monographia Tuberacearum 40, Tab. III fig. XIX (1831)
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Synonyms:
Tuber cibarium Corda (1842), Icones fungorum 5:68, t. 5 f. 46
Tuber bituminatum Berkeley et Broome(1851), Ann. & Mag. Nat. Hist., Ser. II 7: 183
Tuber culinare Zobel var. mesentericum (Vittadini) Zobel (1854), in (Corda) Zobel Iconum fungorum 6: 82
Tuber culinare Zobel var. tesserulatum Zobel (1854), in (Corda) Zobel Iconum fungorum 6: 83
Tuber culinare Zobel var. tulasneanum Zobel (1854), in (Corda) Zobel Iconum fungorum 6: 83
Tuber culinare Zobel var. lespiaultianum Zobel (1854), in (Corda) Zobel Iconum fungorum 6: 83
Tuber culinare Zobel var. rabenhorstii Corda (1854), in (Corda) Zobel Iconum fungorum 6: 83, t. 18 f. 13
Tuber mutabile Quélet (1881), C. R. Ass. franç. Av. Sc. (Reims, 1880) 9: 671, t. 8 f. 14
Tuber bituminatum Berkeley et Broome var. ellipsosporum Ferry de la Bellone (1888), La Truffe 144
Tuber maresa Font Quer (1930), in Codina & Font Quer Cavanillesia 3: 179 (1930)
Tuber aestivum Vittadini var. mesentericum (Vittadini) Trappe (1979), Mycotaxon 9(1): 311, t. 3 f. 29c
Macroscopic characters:
Ascomata: hypogeous, subglobose or irregular in shape, with a basal cavity, 2–3 (–6) cm across, blackish-brown to black, conspicuously warted. Warts 2–8 mm across, generally smaller than those of Tuber aestivum, pyramidal, 4–6-sided, sometimes flattened.
Gleba: firm, solid, dark brown at maturity, darker than that of Tuber aestivum, marbled with white, meandering veins that do not change colour when exposed to air. Veins often arise from the basal cavity and are radially arranged.
Odour: strong and distinctive, phenolic, bitumen-like or iodine, varying considerably between collections. The odour weakens on exposure to air, sometimes becoming pleasant and reminiscent of Tuber melanosporum.
Taste: intense, sometimes unpleasant, slightly bitter, and occasionally reminiscent of bitter almonds.
Habitat:
Distribution poorly known due to frequent confusion with Tuber aestivum and Tuber uncinatum. Forms mycorrhizas with the roots of several trees: oaks (Quercus), beeches (Fagus sylvatica), hazels (Corylus) and pines (Pinus). Inhibits plant growth and produces “burns”. Ripens from September to January. Found in shady forests of holm oaks, pines and beeches.
Notes:
Tuber mesentericum is very similar to Tuber aestivum and has variously been synonymised with or treated as a variety of that species, but molecular analyses have demonstrated that they are two distinct species. The presence of a basal cavity and the phenolic odour distinguish it from Tuber aestivum, though not from Tuber uncinatum, which can also have a basal cavity and a similar odour. Tuber mesentericum is little appreciated on account of its strong, unpleasant smell.
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Microscopic characters:
Asci: globose to subglobose, sessile or short-stalked, 70–100 × 45–75 µm, 1–5 (–6)-spored (usually 3–4-spored).
Ascospores: 25–52 (–57) × 19–37 µm excluding ornament, size variable depending on the number of spores per ascus, Q range = 1.40–1.83, ellipsoid to subglobose, yellow, translucent, ornamented with a coarse irregular reticulum 3–5 µm high, sometimes bent at the apex. Meshes variable, usually 3–5 across the width of the spore, often with incomplete secondary crests inside.
Peridium: pseudoparenchymatous.
 | Antonio Rodríguez trufamania@gmail.com antonio@trufamania.com |