Fungi form a ubiquitous group of largely inconspicuous organisms that play key ecological roles in terrestrial
nutrient cycling. The typically subterranean or otherwise unnoticeable nature of fungal life has left mycology with a
partial understanding of fungal biology, and progress is hampered by factors such as the difficulty to delimit species and
individuals of fungi and the sparsity of discriminatory morphological and physiological characters for reliable species
identification. These and other complications have paved the way for DNA sequence data as an important source of
information in mycology, and there are now twenty years’ worth of fungal sequence data available for scientific purposes.
However, issues of data reliability and generality impede the use of publicly available fungal DNA sequences. The
UNITE database for molecular identification of fungi (http://unite.ut.ee) was built as a response to the difficulties facing
anyone seeking to identify environmental samples of fungi to species level using molecular data and the major
international sequence databases. The present study describes the UNITE database and examines the role of UNITE in the
light of emerging sequencing technologies, notably massively parallel (“454”) pyrosequencing. Environmental sampling
of fungi is discussed from a taxonomic perspective.