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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Poplar > Fungi growing on trunks or branches

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Poplar > Trunk/Branches > Fungi growing on trunks or branches

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  • Image: Trunk and limb rot 1
  • Image: Trunk and limb rot 2
  • Image: Trunk and limb rot 3

Trunk and limb rot
Phellinus tremulae

  • Fungal fruiting bodies arise along the stem, near a pruning wound, crack or other wound
  • Fruiting bodies are up to 8 inches wide to 6 inches thick; lower surface at 45 degree angle
  • Fungal surface is pale brown when young to black and crusted when aged
  • The canopy may show no symptoms or may have small yellowing leaves/dead branches depending on the extent of the trunk decay
  • In cross section of the trunk, the wood at the center is discolored, soft, crumbling, stringy or spongy
  • More information on Trunk and limb rot...
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  • Image: Ganoderma root and butt rot 1
  • Image: Ganoderma root and butt rot 2
  • Image: Ganoderma root and butt rot 3

Ganoderma root and butt rot
(aka. artist's conk)
Ganoderma applanatum

  • Fungal conks, a semicircle shelf fungi, can be found from the base of the tree up to 3 feet high on the trunk
  • Conks are reddish brown and shiny on top, white and porous underneath, a rim of white may be visible on the edge of
    growing conks
  • Infected wood at tree base is white, soft, stringy or spongy
  • Infected trees frequently break or fall over in storms
  • Leaves are smaller in size and turn yellow earlier than normal
  • Canopy appears thin with few leaves and multiple dead branches
  • More information on Ganoderma butt rot...
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  • Image: Armillaria root rot 1
  • Image: Armillaria root rot 2
  • Image: Armillaria root rot 3

Armillaria root rot
Armillaria spp.

  • Clusters of honey-colored mushrooms may grow at the base of the tree in fall
  • Wood is decayed, white, soft and spongy, and this may extend from the base of the tree well up into the trunk
  • Infected trees have poor growth, dead branches in the upper canopy, undersized and/or yellow leaves
  • Flat white sheets of fungal growth (mycelia fans) grow between the bark and sapwood at the base of infected trees
  • Thick black, shoestring-like fungus can sometimes be seen under the bark, around roots and in the soil around the base of the tree
  • More information on Armillaria root rot...

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