Mushrooms: The Extent of the Unexplored Potential

This is the authors' abstract. We don't add key points for this paper.

Recent estimates of the number of fungi on Earth range from 500K to 9.9 million species, of which 74−120K are named. A working figure of 1.5 million species is generally accepted, and new data suggests that is not unreasonable. Mushrooms, the definition of which is discussed, constitute at least 14K and perhaps as many as 22K known species. Most new mushrooms are being discovered in the tropics, especially those forming ectomycorrhizas with native trees. In various tropical areas, 22−55 (−73)% of mushroom species have proved to be undescribed. However, collections made over periods of a few years or less underestimate the species actually present. Further, many morphologically defined mushroom "species" prove to be assemblages of many biological species; the existence of cryptic species means that the number of known species may be an underestimate by a factor of at least five. The number of mushrooms on Earth is estimated at 140K, suggesting that only 10% are yet known. This figure was calculated by extrapolation of the proportion of mushrooms in the known fungi (18.75%) to the overall 1.5 million species estimate, with reductions to allow for the extent of novelty actually being found and a conservative allowance for numbers of cryptic species. The implications of this finding for the medicinal and nutritional exploitation of mushrooms are considered.