Oak Sudden Death with White Film Under Bark: Hypoxylon Canker or Armillaria Root Rot—Remove Tree Immediately

Oak with bark loss and white film

Two Likely Fatal Diseases

Hypoxylon canker: Bark falls off, revealing gray/black fungus. Tree near death. TX Forest Service | OK Fact Sheet
Armillaria root rot: Roots rot, fungus invades lower trunk. White mycelial fans under bark. USFS | Rainbow Tree Care

Remove affected tree ASAP to reduce spore load. Other oaks may already be infected. Compare photos to fact sheets; follow up with questions.

Plant Diseases: Sapsucker Damage on Young Oak: Same Culprit, Different Tree; Advanced Maple Trunk Decay: No Magic Bullet, Focus on Vigor and Safety; Oak Trunk Green/White Growth: Lichens, Not Disease; Oak Burls: Harmless Oddities Prized by Woodworkers; Plum Tree Loose Bark with Magenta Spores: Complex Diagnosis Needed; Silver Oak Termite Damage: Internal Decay Likely Terminal; Oak Tree Weeping Sap: Borer Infestation and Treatment; Bark Beetle Damage on Elm: Signs and Last-Resort Treatment; Maple Trunk Bark Peeling: Wound Care (Bark Scoring); Oak Borer Infestation: Dark Rotted Spot on Trunk

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