Truffles are fungi of the genus Tuber. They belong to Division Ascomycota (fungi that appear as spheres or sacs; traditional mushrooms belong to Division Basidiomycota). Truffles are highly valued for their taste and as a result are very expensive. Truffles grow in association with trees, usually oaks, beeches, poplars, and hazels. The fruiting body emerges in autumn. Most of the truffles used for food come from Europe or China. A few of the less commonly utilized species reside in the Pacific Northwest of North America. There are two types of truffles: black truffles and white truffles. The chocolate candy truffle is named for its resemblance to the truffle fungi, not for having the truffle as an ingredient.