Powderpuff bracket

Postia ptychogaster

Postia ptychogaster is a species of mushroom-forming fungus that occurs on conifer stumps and logs on the ground in moist, shaded woodlands. It is often one of the last species to be involved in the wood decay process, and appears on substrates where the decomposition process is already well established. The fruiting body is unusual for a bracket fungus in that it begins as a solid mass of white to buff powder. This anamorphic (asexual) stage is a dense, cushion-like structure of mycelium, and is made up of billions of chlamydospores. The fruiting body takes several months to mature into a polypore with the typical spore-bearing pores [1][2].

The species occurs only on lignin-rich substrates, and appears to be involved in speeding up the last phases of the decomposition process. Nutrients contained in the lignin and cellulose remnants of the wood are released, allowing microbial biomass to thrive, and also allow the substrate to be further colonised by other fungal and bacterial species. P. ptychogaster is therefore an important part of the forest ecosystem, allowing the completion of the nutrient cycle, enriching the soil, and contributing to overall forest health [2][3][4].

The rather ephemeral, powdery transitional form of Postia ptychogaster can make it easy to overlook or otherwise mistake for mold or dust [5].

[1] NatureSpot.“Powderpuff Bracket – Postia ptychogaster.” NatureSpot Species Guides. https://www.naturespot.org/species/postia-ptychogaster

[2] Siegel, Noah, and Christian Schwarz.“Postia ptychogaster.” California Fungi: MykoWeb. https://www.mykoweb.com/CAF/species/Postia_ptychogaster.html

[3] Forest Pests of Europe.“Postia ptychogaster / Powderpuff Bracket.” ForestPests.eu. https://www.forestpests.eu/pest/postia-ptychogaster

[4] Plantiary.“Powderpuff Bracket (Postia ptychogaster) Mushroom Identification, Habitat & Uses.” Plantiary Species Database. https://plantiary.com/mushroom/postia-ptychogaster_2321.html

[5] NatureSpot.“Powderpuff Bracket – Postia ptychogaster.” NatureSpot Species Guides. https://www.naturespot.org/species/postia-ptychogaster