Tuberum tertium genus Mattioli (1544), Di Pedacio Dioscoride Anarzabeo sensu Fries (1823)
Tuber rufum Pollini (1816), Plant. Nov. 33 sensu Fries (1823)
Tuber rufum Pollini: Fries (1823), Systema mycologicum 2 Pt. II: 292
Tuber cinereum Tul et C. Tul (1844) Giorn. Bot. Ital. anno 1, 2 (1): 62
Tuber bonneti Roumeguère (1882), Rev. Mycol. 4(14): 76, t. 26 f. 1
Tuber rufum Pico var. oungloun Bonnet in Roumeguère Funghi gallici exsiccati nº 2816
Tuber lucidum Bonnet (1884), Rev. Mycol. 6(23): 139
Tuber caroli Bonnet (1885), Rev. Mycol. 7: 8
Tuber rutilum R Hesse (1894), Die Hypogaeen Deutschlands 2: 13, t. 16 f. 5
Tuber rufum Pico var. rufum forma rufum Montecchi & Lazzari (1993), Atlante Fotografico di Funghi Ipogei (Trento): 191 (1993)
Ascomata: hypogeous, subglobose or irregular in form, sometimes with a basal depression, 1–4 cm in size, reddish brown, yellow brown, blackish, areolate or minutely warted. Warts minute, pyramidal, flattened.
Gleba: hard, solid, whitish at first, becoming light-brown, dark-brown at maturity, marbled with two kinds of numerous, thin, branching veins: the one kind dark-coloured and contain no air (venae lymphaticae, veines aquiferes of Tulasne, venae internae of Vittadini), the other white and conveying air (air-veins, veines aeriferes, venae externae)
Taste: faint, little persistent, nutty, somewhat tannic.
Widespread species associated with deciduous trees and conifers, ripening in late autumn and winter, although you can find them year-round. We harvest them under holm oaks, in calcareous soils, in the same habitat as Tuber melanosporum and Tuber aestivum. They are often under thymes.
The variability of this species, both macroscopically and shape and size of the spores, has led to the creation of many different varieties and even new species.
Tuber ferrugineum Vittadini (=Tuber rufum f. ferrugineum (Vittad.) Montecchi et Lazzari) has a brown, minutely papillose peridium with a soft gleba. Tuber requienii Tul et C. Tul is considered by some authors synonymous with Tuber ferrugineum.
Tuber rufum forma lucidum (Bonnet.) Montecchi & Lazzari has a bright black peridium.
Tuber bonneti Roumeguère, synonymized or considered a variety of Tuber rufum, has very small spores (19–22 x 9–12 µm)
Tuber rufum Pico var. nigrum Mattirolo (=Tuber rufum Pico var. oungloun Bonnet, =Tuber rufum Pico f. melanica Cetto) has a black, warted peridium, with flattened, pyramidal warts and large, ellipsoid spores, up to 45 x 28 µm
Asci: subglobose to broadly clavate or pyriform, long or short-stalked, 50–80 x 40–70 µm excluding stalk, 1–4 (–6)-spored (usually 3–4-spored)
Ascospores: 18–29(–35) x 15–20(–27) µm excluding ornament, size variable depending on number of spores in the ascus, Q range = 1,15–1,57, broadly ellipsoid to ovate ellipsoid, yellow ochre, translucent, ornamented with conical spines, separate, 2–4(–5) µm long.
Peridium: 400–500 µm thick, composed of agglutinated, interwoven hyphae (texture intricata), becoming pseudoparenchymatous towards the surface and forming subglobose, thick-walled cells , in a superficial layer 50 µm thick.