Inkspot of aspen

Inkspot of aspen - Sclerotia of <em>Ciborinia whetzelii</em> on aspen
  • Latin name: Ciborinia bifrons (Whetzel) Whetzel
  • French name: Tache d'encre
  • Division: Ascomycota
  • Class: Helotiales
  • Synonym(s): Ciborinia whetzelii (Seaver) Seaver,
    Sclerotinia whetzelii Seaver,
    Sclerotinium bifrons Ellis & Everh. ex. Sacc. & Syd.
Description

Micro-habitat(s)

Leaf

Distribution

Canada

Damage, symptoms and biology

Brown areas with concentric white zones appear on infected leaves in early summer. By midsummer, the spots coalesce and the entire leaf turns brown. Sclerotia develop in the dead tissues. In late summer, the sclerotia fall out, leaving the infected leaves riddled with holes. The sclerotia overinter in the debris in the litter. During the wet weather of late spring, they form spore-bearing fruiting bodies. The spores are released into the air and infect new leaves.

Light infections are inconsequential. However, repeated infections can kill small trees and weaken larger trees, which can die if exposed to other stress factors.

Canadian Forest Service Publications

Inkspot of aspen

Information on host(s)

Main host(s)

Hybrid poplar, largetooth aspen, trembling aspen

Photos
  • Inkspot of aspen Sclerotia of Ciborinia whetzelii on aspen
  • Inkspot of aspen Ink spots caused by Ciborinia whetzelli. The spots are the stage of the fungus that will overwinter.
  • Inkspot of aspen Trembling aspen infected by Ciborinia whetzelli, the causal agent on ink spot of aspen.
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