Sawadaea bicornis

Sawadaea bicornis
Sawadaea bicornis on Acer
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Leotiomycetes
Order:	Helotiales
Family:	Erysiphaceae
Genus:	Sawadaea
Species:	S. bicornis
Binomial name
Sawadaea bicornis (Wallr.) Homma, 1937

Sawadaea bicornis is a species of powdery mildew in the family Erysiphaceae. It is found across the world, where it affects maples (genus Acer ).

Description

The fungus forms thin, white irregular patches on the leaves of its host. Sawadaea bicornis affects many species in the genus Acer, including Acer macrophyllum , A. campestre , A. pseudoplatanus, A. negundo, A. grandidentatum, A. tataricum, A. circinatum, A. saccharinum, and A. platanoides. Some of these species can also be affected by Sawadaea tulasnei so care should be taken to distinguish the two. ^[1]

Taxonomy

The fungus has two different formae. S. bicornis f. bicornis affects Acer campestre and A. planatoides . S. bicornis f. polyphaga is a more virulent form that has evolved to infect a much larger range of host species and is introduced across the world. ^[2]

References

1. Braun, Uwe; Cook, Roger T. A. (2012). Taxonomic manual of the Erysiphales (powdery mildews). CBS biodiversity series. Utrecht: CBS-KNAW fungal biodiversity centre. ISBN   978-90-70351-89-2.
2. Feng, J.; Guan, G.X.; Wu, X.L.; Liu, S.Y.; Song, J.G.; Bradshaw, M.; Götz, M.; Braun, U.; Takamatsu, S.; Heluta, V.; Jin, D.N.; Wang, S.B.; He, Y.H.; Zhang, Z.Y.; Liu, L. (2025). "Phylogeny and taxonomy of Acer powdery mildews, including genera Sawadaea and Takamatsuella (Erysiphaceae, Ascomycota)". Studies in Mycology. doi: 10.3114/sim.2025.112.01 . ISSN   0166-0616.