[5] Black truffles associate with oaks, hazelnut, cherry, and other deciduous trees and are harvested in late autumn and winter.

[8] Burgundy truffles (designated Tuber uncinatum, but the same species) are harvested in autumn until December and have aromatic flesh of a darker colour.

[8] Tuber magnatum, the high-value white truffle (Italian: tartufo bianco) is found mainly in the Langhe and Montferrat areas[9] of the Piedmont region in northern Italy, and most famously, in the countryside around the cities of Alba and Asti.

The "whitish truffle" (Tuber borchii) is a similar species native to Tuscany, Abruzzo, Romagna, Umbria, the Marche, and Molise.

Oregon celebrates its traditional truffle harvesting with a 'truffle festival', combined with culinary shows and wine tastings.

[1] Pinus edulis, a widespread pine species of the Southwest US, is dependent on Geopora for nutrient and water acquisition in arid environments.

[21] Members of this genus have low host specificity, associating with a variety of plants including hardwoods, forbs, shrubs, and grasses.

[21] The phylogeny and biogeography of the genus Tuber was investigated in 2008[25] using internal transcribed spacers (ITS) of nuclear DNA and revealed five major clades (Aestivum, Excavatum, Rufum, Melanosporum and Puberulum); this was later improved and expanded in 2010 to nine major clades using 28S large subunits (LSU) rRNA of mitochondrial DNA[citation needed].

[27][28][29] Phylogenetic analysis has revealed that basidiomycete subterranean fruiting bodies, like their ascomycete counterparts, evolved from above ground mushrooms.

The mycelia of truffles form symbiotic, mycorrhizal relationships with the roots of several tree species, including beech, birch, hazel, hornbeam, oak, pine, and poplar.

Because truffle fungi produce their sexual fruiting bodies underground, spores cannot be spread by wind and water.

Flying squirrels, Glaucomys sabrinus, of North America play a three-way symbiosis with truffles and their associated plants.

[35] In truffle fungi, as in all ectomycorrhizae, the majority of nutrient exchange occurs in the Hartig net, the intercellular hyphal network between plant root cells.

Mycorrhizal fungi are much smaller than fine roots, so they have a higher surface area and a greater ability to explore soils for nutrients.

[49] A foundation species in arid-land ecosystems of the Southwest United States is Pinus edulis, commonly known as pinyon pine.

[50] Associated ectomycorrhizal fungi will likely play a significant role in the survival of P. edulis with continuing global climate change.

[citation needed] Because truffles are subterranean, they are often located with the help of an animal (sometimes called a truffler[52]) possessing a refined sense of smell.

Dogs offer an advantage because they do not have a strong desire to eat truffles, so they can be trained to locate sporocarps without digging them up.

[53] Fly species of the genus Suillia can also detect the volatile compounds associated with subterranean fruiting bodies.

[53] The mycelia or fruiting bodies release the volatile constituents responsible for the natural aroma of truffles or derive from truffle-associated microbes.

The chemical ecology of truffle volatiles is complex, interacting with plants, insects, and mammals, which contribute to spore dispersal.

[57] Truffles long eluded techniques of cultivation, as Jean-Anthelme Brillat-Savarin (1825) noted: The most learned men have sought to ascertain the secret and fancied they discovered the seed.

[63] The situation changed in the late 1960s and early 1970s, with researchers in France and Italy establishing mycorrhizas with truffle spores.

[citation needed] Investments in cultivated plantations are underway in many parts of the world using controlled irrigation for regular and resilient production.

Complete soil analysis to avoid contamination by other dominant fungi and very strict control of the formation of mycorrhizae are necessary to ensure the success of a plantation.

In June 2014, a grower harvested Australia's largest truffle from their property at Robertson, in the Southern Highlands of New South Wales.

[73] At its peak in the 2008–2009 season, one farm produced about 200 pounds of truffles, but Eastern filbert blight almost entirely wiped out the hazel trees by 2013 and production dropped, essentially ending the business.

As the volatile aromas dissipate quicker when heated, truffles are generally served raw and shaved over warm, simple foods which highlight their flavour, such as buttered pasta or eggs.

Thin truffle slices may be inserted into meats, under the skins of roasted fowl, in foie gras preparations, in pâtés, or in stuffings.

Many commercial producers use 2,4-dithiapentane regardless, as it has become the dominant flavour most consumers, unexposed to fresh truffles but familiar with oils, associate with them.