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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Oak > Unusual color on branch or trunk

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Oak > Trunk/Branches > Unusual color on branch or trunk

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  • Image: Smooth Patch 1
  • Image: Smooth Patch 2
  • Image: Smooth Patch 3

Smooth Patch
Aleurodiscus spp. and Dendrothele spp.

  • Sunken, relatively smooth, round to irregular area of bark on trunk or branches
  • Affected bark is often lighter in color
  • Small cream colored disks or saucer like fungal spore producing structures grow within affected area
  • Has no affect on the overall health of the tree
  • More information on Smooth Patch...
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  • Image: Lichens 1
  • Image: Lichens 2
  • Image: Lichens 3

Lichens
Several species

  • Colorful patches on the bark of trunk and/or branches
  • Can be wrinkled, in scalloped sheets, lace-like pads, bushy tufts, paint-like spots or splashes
  • Forms can be flat against the bark surface or raised in leaf-like lobes, finger-like or hairy projections
  • Colors may be shades of gray, green, blue, yellow, orange, or red
  • More information on Lichens...
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  • Image: Botryosphaeria 1
  • Image: Botryosphaeria 2

Botryosphaeria
Botryosphaeria quercuum

  • Leaves on random branch tips throughout the canopy wilt, turn brown and remain attached to twig
  • Cankers with brown to black, sunken cracked bark can be found at the base of wilted twigs
  • If bark is peeled back from the canker, brown streaks can be seen in the sapwood
  • Small black raised pimple like fungal fruiting bodies can be seen scattered on infected twigs
  • Cankers only occasionally extend into larger branches
  • Damage easily confused with twig girdler damage

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