Taphrina betulae (Fuckel) Johanson, 1886
on Betula

Betula pendula, Belgium, prov. Antwerp, Dessel, den Hof, 11.vi.2018 © Carina Van Steenwinkel

leaf spots

leaf spots upper side

underside

asci

asci with few, relatively large spores

two asci on tneir basal cell

ascospores
gall
The gall resembles the one by T. carnea, but is much less strongly expressed: isolated leaves have spots (± 1 cm), and only young leaves have bulges. At maturity the surface is lined with a layer of 20-50 µm high asci, each one on a basal cell.
hostplants
Betulaceae, monophagous
Betula pendula, pubescens, turkstanica.
references
Abras, Fassotte, Chandelier & Cavelier (2008a), Bacigálová, Mułenko & Wołczańska (2005a), Brandenburger (1985a: 53), Buhr (1964b), Dauphin & Aniotsbehere (1997a). Doppelbauer & Doppelbuar (1973a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Mix (1949a)