Pacific Northwest Plant Disease Management Handbook

Cleistothecium (pl. Cleistothecia)

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Latest revision: 
March 2024
Cleistothecia

Cleistothecia squashed open to show several asci with ascospores of Erysiphe necator.

Photo by Melodie Putnam, 1998.

Closed, usually spherical, ascus-containing structure of powdery mildew fungi, also known as a chasmothecium. A sexual fruiting structure.

Pscheidt, J.W., and Ocamb, C.M. (Senior Eds.). 2024 Pacific Northwest Plant Disease Management Handbook.
© Oregon State University.

Use pesticides safely!

  • Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
  • Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
  • Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.

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H - Home garden packaging commonly available.     O - Acceptable in organic production.