Hemlock - Blueberry rust

• French disease name: Rouille de la pruche et du bleuet
• Pathogen name: Naohidemyces vaccinii (Wint.) Sato, Katsuya et Hiratsuka
• Kingdom: Fungi
• Phylum: Basidiomycota
• Class: Pucciniomycetes
• Order: Pucciniales
• Family: Milesinaceae

Distribution

• Western Canada

Damage, symptoms and biology

Damage to either host is negligible and localized in areas where hemlock regeneration grows intermingled with huckleberries and blueberries.

Other information

Until recently, this rust was considered a part of the genus Pucciniastrum. However, because of the unique structure of its aecia, it has been placed in the genus Naohidemyces. Another needle rust, Melampsora epitea, which is also found on hemlock, could be confused with N. vaccinii. The aecia of M. epitea are "loose," with no peridium covering the aeciospores, while those of N. vaccinii have a dome-shaped covering with a centrally located hole (ostiole) through which spores are released.

Canadian Forest Service Publications

Hemlock - Blueberry rust

Information on host(s)

Main host(s)

• Eastern hemlock
• Mountain hemlock
• Western hemlock

Photos

Echinulate aeciospores of N. vaccinii and dome-shaped aecium

David Lai

Echinulate urediniospores

David Lai

Discoloured hemlock needles resulting from Naohidemyces vaccinii infection

Eric Allen

Discoloured hemlock needles resulting from Naohidemyces vaccinii infection (upper needle sufaces)

Eric Allen

Discoloured hemlock needles resulting from Naohidemyces vaccinii infection (lower needle surfaces)

Eric Allen

Aecia on the lower surface of hemlock needles

Eric Allen

Uredinia on Vaccinium (blueberry)

Eric Allen