Geosmithia

Geosmithia is a genus of anamorphic fungi of uncertain familial placement in the order Hypocreales. The genus, circumscribed by Australian mycologist John Pitt in 1979,^[1] is widely distributed. A 2008 estimate placed ten species in the genus,^[2] but several new species have since been described. Thousand cankers disease, which affects economically important black walnut (Juglans nigra) populations in North America, is caused by Geosmithia morbida.^[3]

Geosmithia
Geosmithia morbida on leaves of black walnut
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Sordariomycetes
Order:	Hypocreales
Family:	incertae sedis
Genus:	Geosmithia Pitt (1979)
Type species
Geosmithia lavendula (Raper & Fennell) Pitt (1979)

Species in the genus are generally similar to those in Penicillium, but can be distinguished from them by forming cylindrical conidia from rough-walled phialides. Additionally, the conidia of Geosmithia do not have a green color, in contrast to the characteristic blue-grey or green-grey conidia of Penicillium. Some Geosmithia species have teleomorphic forms that are classified in the genus Talaromyces. However, Geosmithia is a polyphyletic taxon with evolutionary affinities to at least three groups of the euascomycete lineage within the Ascomycota.^[4] The generic name Geosmithia honors British mycologist George Smith.^[1]

Species

As accepted by Species Fungorum;^[5]

• Geosmithia brunnea Y.T. Huang, M. Kolařík & Hulcr (2017)
• Geosmithia carolliae A.O.B. Cunha, A.R. Machado & Souza-Motta (2018)
• Geosmithia cnesini M. Kolařík & Kirkendall (2015)
• Geosmithia eburnea Yaguchi, Someya & Udagawa (1994)^[6]
• Geosmithia emersonii (Stolk) Pitt (1979)
• Geosmithia eupagioceri M. Kolařík (2010)^[7]
• Geosmithia fassatiae M. Kolařík, Kubátová & Pažoutová (2005)^[8]
• Geosmithia flava M. Kolařík, Kubátová & Pažoutová (2004)
• Geosmithia langdonii M. Kolařík, Kubátová & Pažoutová (2005)^[8]
• Geosmithia lavendula (Raper & Fennell) Pitt (1979)
• Geosmithia malachitea Yaguchi & Udagawa (1993)^[9]
• Geosmithia microcorthyli M. Kolařík (2010)
• Geosmithia morbida M. Kolařík, Freeland, C. Utley & Tisserat (2010)
• Geosmithia namyslowskii (K.W. Zaleski) Pitt (1979)
• Geosmithia obscura M. Kolařík, Kubátová & Pažoutová (2005)^[8]
• Geosmithia omnicola Pepori M. Kolařík, Bettini, Vettraino & Santini (2015)
• Geosmithia proliferans Y.T. Huang, M. Kolařík, Kasson & Hulcr (2017)
• Geosmithia putterillii (Thom) Pitt (1979)
• Geosmithia rufescens M. Kolařík (2010)^[7]
• Geosmithia swiftii Pitt (1979)
• Geosmithia tibetensis Y.M. Wu & T.Y. Zhang (2013)^[10]
• Geosmithia ulmacea Pepori, M. Kolařík, Bettini, Vettraino & Santini (2015)
• Geosmithia xerotolerans Rodr.-Andr., Cano & Stchigel (2018)

Former species;^[5]

• G. argillacea (Stolk, H.C. Evans & T. Nilsson) Pitt (1979) = Rasamsonia argillacea Aspergillaceae family
• G. cylindrospora (G. Sm.) Pitt (1979) = Rasamsonia cylindrospora Aspergillaceae
• G. pallida (G. Sm.) M. Kolařík, Kubátová & Pažoutová (2004) = Geosmithia putterillii
• G. viridis Pitt & A.D. Hocking (1985) = Talaromyces viridulus Aspergillaceae