Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya

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English n/a Status LU: established. 1st record: 2012.
Lëtzebuergesch Falsche wäisse Stillbecherchen Status Eur.: established.
Français n/a RA: ISEIA: A3. Harmonia+: 0,16.
Deutsch Falsches weißes Stängelbecherchen Wikipedia: Wikipedia - English - Hymenoscyphus pseudoalbidus Wikipedia - Français - Chalara fraxinea Wikipedia - Deutsch - Falsches Weißes Stängelbecherchen Wikipedia - Nederlands - Chalara fraxinea | Wikispecies: n/a (2020) | CABI
Nederlands Vals essenvlieskelkje Back to the list of neomyceta

Report the species

Report Hymenoscyphus fraxineus to the National Museum of Natural History.

Brief description

Hymenoscyphus fraxineus, Park in Colmar-Berg, June 6th 2014. Picture by Christian Ries, June 6th 2014.

Crown dieback in ash tree infected by Hymenoscyphus fraxineus near Colmar-Berg. Photo: Christian Ries, June 6th 2014.

Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya (Baral et al. 2014) is an ascomycete fungus that causes ash dieback, a chronic fungal disease of ash trees (Fraxinus excelsior) in Europe characterised by leaf loss and crown dieback in infected trees. It was first described in Japan (Zhao et al. 2012).

Hymenoscyphus fraxineus is an invasive anamorphic fungal pathogen which comes from the Far East and has greatly expanded its reach throughout Central and Western Europe in recent years. Studies of herbarium material show that Hymenoscyphus fraxineus was already present in Central Europe in 1978 (Queloz et al. 2011). It is now entrenched in Europe. It is closely related to a native fungus Hymenoscyphus albidus, which is saprotrophic and also grows on the petioles of dead leaves of ash trees.

The entire natural range of known hosts, including North Africa, Russia and south-west Asia, is currently threatened by ash dieback, with large areas already affected. Little is known about the susceptibility of the other species of ash in temperate zones (CABI 2019).

Hymenoschyphus fraxineus, Neudorf, Luxembourg. Photo par Guy Marson, June 2012.

Hymenoschyphus fraxineus, Neudorf, Luxembourg. Photo: Guy Marson, June 2012.

Status and distribution in Luxembourg

Records of Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya in Luxembourg. Data source: Recorder-Lux, iNaturalist & GBIF, 2024-05-22.

Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya was first recorded on 16th June 2012 in Bois de Cessange (Municipality of Luxembourg) under its synonym Hymenoscyphus pseudoalbidus (Garnier-Delcourt et al. 2013: 35-36). It was reported in 2002 in Germany (Heydeck et al. 2005) and in 2010 in Belgium (Delhaye et al. 2010). The fungus is rapidly spreading throughout Luxembourg and in 2014 it was found in all regions of Luxembourg: a considerable number of young ash trees are affected while only a part of the elder ash trees show dieback symptoms.

Only few observations have been reported to the Recorder-Lux database so that the map does not reflect the actual distribution of the species, occurring everywhere where ash occurs.

Risk assessment

ISEIA protocol

B3 (3+3+3+1) = Watch List. First assessed on 22 September 2017 by Christian Ries and Yves Krippel.

Harmonia+ protocol

Overall risk score 0,16 = (Overall Invasion score 0,79 x Overall Impact score 0,20) (Non publ. RA by C. Ries).


Worldwide distribution


  • Baral H-O, V Queloz & T Hosoya (2014) Hymenoscyphus fraxineus, the correct scientific name for the fungus causing ash dieback in Europe. IMA Fungus 5(1): 79-80.
  • CABI, 2019. Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-04-28]
  • Garnier-Delcourt M, G Marson, Ch Reckinger, B Schultheis & M-T Tholl (2013) Notes mycologiques luxembourgeoises. VII. Bull. Soc. Nat. luxemb. 114: 35-54. (Pdf 6.5 MB)
  • Heydeck P, M Bemmann, H-G Kontzog (2005) Triebsterben an Gemeiner
    Esche (Fraxinus excelsior) im nordostdeutschen Tiefland. Forst und Holz 60: 505–506.
  • MNHNL, iNaturalist & GBIF, 2020. Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, Hosoya in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [accessed 2020-04-28]
  • Queloz V, C R Grünig, R Berndt, T Kowalski, T N Sieber & O Holdenrieder (2011) Cryptic speciation in Hymenoscyphus albidus. For. Path. 41: 133–142, published online 30 March 2010 – doi:10.1111/j.1439-0329.2010.00645.x
  • Zhao Y-J, T Hosoya, H-O Baral, K Hosaka & M Kakishima (2012) Hymenoscyphus pseudoalbidus, the correct name for Lambertella albida reported from Japan. Mycotaxon 122: 25-41.

 Page content last updated on 2020-09-23. Last proofread by Caroline Grounds on 2019-12-12.