Apiognomonia errabunda (Roberge) von Höhnel, 1918

on woody plants

Apiognomonia errabunda on Tilia x europaea

Tilia x europaea, Belgium, prov. Antwerp, Retie, Prinsenpark 29.vi.2018 © Carina Van Steenwinkel

Apiognomonia errabunda on Tilia x europaea

underside of an infected leaf

Apiognomonia errabunda on Tilia x europaea

like in A. veneta the leaf spots develop from the veins, but they are not angular.

Apiognomonia errabunda on Tilia x europaea

same leaf, underside

Apiognomonia errabunda on Tilia x europaea, blackened petioles

characteristic also is the black discolouration of the petioles.

Apiognomonia errabunda on Tilia x europaea: leaf spot with acervuli

leaf spots with hypophyllous brown acervuli.

Apiognomonia errabunda: conidia

conidia

gall

usually an asymptomatic endophytic leaf fungus. The anamorph causes in spring drying out of buds, die-off of young shoots, and large leaf spots with hypophyllous acervuli. Conidia 4-6 x 10-13 µm. On beech, where the fungus is very common, it may cause the death of the larvae of Hartigiola annulipes and Mikiola fagi (Wulf).

The teleomorph forms black perithecia with a long neck on fallen leaves and dead branches.

hostplants

polphagous

Chamerion angustifolium; Fagus sylvatica; Fraxinus; Quercus petraea, pyrenaica, robus; Rhus glabra; Salix; Sorbus aria; Tilia cordata, x europaea; Ulmus glabra.

synonyms

Gnomonia errabunda (Roberge) Auerswald, 1869; Discula umbrinella (Berkeley & Broome) Morelet, 1973; Apiognomonia tiliae (Rehm) von Höhnel 1920.

notes

Vainio ao witnessed an outbreak of the fungus on Tilia cordata, causing large-scale defoliation, where it was striking that the petioles had turned blackish brown, while the leaf laminas remained green.

references

Brandenburger (1985a: 61, 64), Butin & Kehr (1999a), Ellis & Ellis (1997a), Kozłowska, Mułenko & Heluta (2015a), Melgarejo Nárdiz, García-Jiménez, Jordá Gutiérrez ao (2010a), Roskam (2009a), Ruszkiewicz-Michalska (2006a), Sogonov, Castlebury, Rossman ao (2008a), Vainio, Velmala, Salo ao (2017a), Wulf (1990).

mod 2.vii.2018