Tuber macrosporum

Scientific classification

Kingdom:        Fungi

Division:          Ascomycota

Class:   Pezizomycetes

Order: Pezizales

Family:            Tuberaceae

Genus: Tuber

Species:           T. macrosporum

Binomial name           Tuber macrosporum

Vittad. (1831)

Tuber macrosporum, commonly known as the smooth black truffle, is a species of edible truffle in the family Tuberaceae. Found in Europe, and common in central Italy, the truffle was described as new to science by Italian mycologist Carlo Vittadini in 1831.

The truffles are roughly spherical to irregular in shape, and typically measure 0.5 to 2 cm (0.2 to 0.8 inches) in diameter (rarely are they greater than 5 cm). The surface color ranges from reddish brown to rust to blackish.

Warts on the fruit body surface are low, so that the truffle appears fairly smooth. The truffle flesh is purplish brown to grey-brown with thin white veins.It has an intense garlic-like odor similar to the Italian white truffle (Tuber magnatum). Host plants of T. macrosporum include poplars, hazel, linden, and oaks.

Macroscopic characters:

Ascomata: hypogeous, subglobose or irregular in form and lobed, 1-5 cm in size, warted, reddish brown to blackish. Warts 0,5-2 mm across, polygonal, irregular in form and size, flattened, ridged.

Gleba: firm, solid, brown purplish to black at maturity, marbled with numerous, wide, white, meandering veins.

Odour: strong, pleasant, garlicky, likeTuber magnatum

Taste: strong, pleasant, garlicky, likeTuber magnatum

Tuber macrosporum usually grows in limestones soils and often in clay soils. In Italy, you can find these truffles in the same places as Tuber magnatum. They are associated with the roots of several trees: poplars (Populus), willows (Salix), hazels (Corylus), oaks(Quercus) and lindens (Tilia).

Tuber macrosporum is easily recognizable by the large spores and the low and flattened warts. That truffle sometimes looks almost smooth and receives the popular name of “smooth black truffle”. The first description of this species was probably Tuber cibarium subcinereum alliaceum Bulliard (1791), Histoire Champignons France 74

Tuber macrosporum is is an edible truffle, gastronomically excellent.

Microscopic characters:

Asci: subglobose to ellipsoid, short-stalked, 90-130 x 65-80 µm, 1-3 (-4)-spored (usually 3-spored).

Ascospores: 42-85 x 30-42 (-42) µm excluding ornament, size variable depending on number of spores in the ascus, Q range = 1,40-2,08, ellipsoid, light yellow, brown-reddish at maturity, opaque at maturity, ornamented with a small-meshed reticulum. Meshes polygonal, irregular in form and size, 3-5 (6) µm high, 4-10 µm long, 6-10 across width of spore.

Peridium: 150-300 µm thick, composed of agglutinated, interwoven, thick-walled hyphae, brown- reddish in the outermost layers, yellowish in the innermost layers.