<P> The origin of the word truffle appears to be the Latin term tūber, meaning "swelling" or "lump", which became tufer - and gave rise to the various European terms: Croatian tartuf / тартуф, Danish trøffel, Dutch truffel, English truffle, French truffe, German Trüffel, Italian tartufo, Polish trufla, Romanian trufă, Spanish trufa, and Swedish tryffel . </P> <P> The German word Kartoffel ("potato") is derived from the Italian term for truffle because of superficial similarities . In Portuguese, the words trufa and túbera are synonyms, the latter closer to the Latin term . </P> <P> The mycelia of truffles form symbiotic, mycorrhizal relationships with the roots of several tree species including beech, birch, hazel, hornbeam, oak, pine, and poplar . They prefer argillaceous or calcareous soils that are well drained and neutral or alkaline . Truffles fruit throughout the year, depending on the species, and can be found buried between the leaf litter and the soil . </P> <P> The phylogeny and biogeography of truffles was investigated in 2008 using internal transcribed spacers (ITS) of nuclear DNA with five major clades (Aestivum, Excavatum, Rufum, Melanosporum and Puberulum); this was later improved and expanded in 2010 to nine major clades using large subunits (LSU) of mitochondrial DNA . The Magnatum and Macrosporum clades were distinguished as distinct from the Aestivum clade . The Gibbosum clade was resolved as distinct from all other clades, and the Spinoreticulatum clade was separated from the Rufum clade . </P>

What kind of tree do truffles grow under
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