Rhabdocline, Swiss Needle Cast and Didymascella

Needle Disease

Rhabdocline pseudotsugae - on Douglas-fir

Rhabdocline apothecia

Apothecia on needles as they appear when dry.

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Another slightly higher magnification of apothecia when dry.


Apothecia swell up when wet and asci will release ascospores.


Phaeocryptopus gaeumannii - Swiss Needle Cast on Douglas-fir

Swiss needle cast perithecia

Douglas-fir with Swiss needle cast. Perithecia (numerous small black dots) can often be seen even without a hand lens if needles are inspected closely.

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Perithecia emerging from stomata on infected needles are easily seen with a hand lens.

Didymascella thujina - on Western Red Cedar

Western red cedar needle disease

Needle lesions when fresh (this is a dried sample) are red containing dark round apothecia.

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Apothecia on lesions of western red cedar produce asci with 2 ascospores per ascus.