Tropical truffles: English translation and critical review of F. von Hohnel's truffles from Java

Truffles are a polyphyletic group of more than 75 genera dispersed among four major fungal lineages, the Ascomycota, Basidiomycota, Glomeromycota, and Zygomycota. Only about 20 truffle species are known from tropical Asia and most are endemic. In 1907-1908, the Austrian botanist and mycologist Franz von Hohnel collected and described five new species of truffles from the island of Java, Indonesia. From three of these five collections, the only existing materials are microscope slides preserved at the Farlow Herbarium of Cryptogamic Botany at Harvard University. The other two collections consist of small packets of fungal material. Considering the high rate of endemism on Java coupled with the destruction of many of the island's natural ecosystems, it is important to preserve and review the remaining collections of these fungi. To facilitate studies of tropical Asian truffles, we critically reexamine von Hohnel's Javanese truffle collections and translate his German descriptions and commentaries into English. As part of this review, Sphaerocreas javanicum Hohn. is synonymized with Glomus coremioides (Berk. & Broome) D. Redecker & J.B. Morton, and Gymnomyces javanicus (Henn.) M.E. Sm. & Schmull is proposed as a new combination for Hydnangium javanicum Henn.