Podosphaera clandestina

Podosphaera clandestina
Podosphaera clandestina on Crataegus in the UK.
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Leotiomycetes
Order:	Erysiphales
Family:	Erysiphaceae
Genus:	Podosphaera
Species:	P. clandestina
Binomial name
Podosphaera clandestina (Wallr.) Lév., 1851
Synonyms
Alphitomorpha clandestinaWallr., 1819 Erysibe clandestina(Wallr.) Link, 1824 Erysiphe clandestina(Wallr.) Fr., 1829 Erysiphe oxyacanthaeDC., 1815 Alphitomorpha oxyacanthae(DC.) Wallr., 1819 Podosphaera oxyacanthae(DC.) de Bary, 1870 Podosphaera kunzeiLév., 1851

Podosphaera clandestina is a species of powdery mildew in the family Erysiphaceae. It is found across the world, where it affects plants in the genera Crataegus , Cydonia and Mespilus . ^[1]

Description

The fungus forms a thin coating on host leaves, typically on young shoots and new branches. Podosphaeraclandestina, like most Erysiphaceae, is fairly host-specific and infects only a few genera. ^[1] Another species of powdery mildew also infects this genus: Phyllactinia mali , which has weak, very thin, often smooth growth, on the undersides of leaves. ^[2]

Taxonomy

The fungus was formally described in 1819 by Wallroth with the basionym Alphitomorpha clandestina. The species was transferred to the genus Podosphaera by Léveillé in 1851.

Podosphaera clandestina is likely a species complex, ^[1] and is comprised of multiple varieties with differing host or geographic ranges and slight microscopic differences. var. clandestina is native to Eurasia and found on various Crataegus species; var. cydoniae is found on Cydonia ; var. luxurians is found on Crataegus in western North American mountains (Colorado); and var. perlonga is found in the American Midwest (Indiana) on the same host genus. Their macromorphology and full geographic ranges are still not yet well known.

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. Bradshaw, Michael; Braun, Uwe; Khodaparast, Seyed Akbar; Mitchell, James K.; Crouch, Uma; Thomas, Jacklyn; Darsaraei, Hamideh; Pfister, Donald H. (2025-07-04). "Phylogeny and taxonomy of the genera of Erysiphaceae, part 7: Phyllactinieae" . Mycologia. 117 (4): 640–700. doi:10.1080/00275514.2025.2476375. ISSN   0027-5514. PMID   40258175.