Tuber mesentericum

Morphological Features:

Fruiting body practically spherical in younger specimens, but adopting somewhat variable shapes as it matures, oblong and irregular, without excessive protuberances, featuring a characteristic cavity at the base. It is rather small in size, ranging from 2 to 4 cm in diameter, occasionally reaching 6 or 7 cm. Dark brown to black in color, fairly uniform. It does not exhibit any type of dehiscence and is entirely warty.

Peridium very dark brown or practically black at times, entirely covered by pyramidal warts that in our collection measure between 3 and 6 mm wide at the base. They are highly interwoven with each other, sometimes featuring grooves, and project upward less prominently than in other similar species. They may occasionally be flattened, though they are predominantly pointed at the apex.

Gleba compact and solid, quite dark brown in color, but provided with whitish veins that typically do not change color upon maturation. It is common, especially in younger specimens, for the veins to exhibit a radial convergence toward the basal region.

Flesh compact and firm, with a strong, pronounced, and rather unpleasant odor reminiscent of tar in our collection, but which also acquires a camphoraceous nuance in enclosed spaces. Its taste is strong and slightly bitter, but nowhere near as unpleasant as the odor.

Habitat:

Like all its congeners, this is a hypogeous species that fruits underground at shallow depths, causing cracks in the soil, and may occasionally sporadically emerge to the surface. It forms mycorrhizal associations with various trees, such as beech, hazel, oak, or holm oak, creating vegetation-free patches around its emergence sites colloquially known as "burned" spots. Our collections were associated with beech (Fagus sylvatica) and hazel (Corylus avellana). It is an early-growing species that does not tolerate cold well, fruiting from spring through the summer months, often sharing habitats with Tuber aestivum.

Observations:

A summer truffle species characterized by an unpleasant odor of tar or camphor, a strong taste, and a dark brown gleba with white veins. For a long time, due to microscopic similarities, this species was synonymized with Tuber aestivum, which has a pleasant odor and taste. Phylogenetic studies have demonstrated what was otherwise obvious: they are two distinct species. In addition to organoleptic characteristics, the described species possesses a typical basal cavity absent in Tuber aestivum. It is a mediocre edible. Tuber uncinatum, which is very similar, is actually an autumnal form of Tuber aestivum.