PollyMapPithomyces sp. mold spore photographed through the microscope in the PollyKit lab — verified in Arizona.
About pithomyces mold spores
Barrel-shaped, warty brown spores from dead grass and leaf litter, common in outdoor air in warm regions.
Where it grows
- Dead grass blades and pasture litter
- Fallen leaves and mulch
- Paper, hay and stored plant material
- Damp indoor surfaces
How to recognize it
Short, thick, barrel- or club-shaped spore divided into a handful of compartments, with a distinctly roughened or warty wall and a broad truncate base.
Typical published size: 15–30 µm
Commonly confused with
- Epicoccum — rounder and without a truncate base
- Alternaria — tapers into a beak
- Ulocladium — smoother wall and egg-shaped outline
Allergy relevance
A moderate mold allergen; part of the general outdoor spore load that can aggravate allergic rhinitis and asthma.
Where it's found
PollyMap has verified specimens of Pithomyces sp. from Arizona.
Widespread in warm and temperate regions of the United States.
Also searched as: pithomyces spore, pithomyces chartarum, pithomyces under microscope.
Related mold specimens
Citing this specimen: PollyMap Specimen Library. “Pithomyces sp. — verified microscope specimen.” pollymap.com/library/specimen/pithomyces-sp-mold-spore-arizona-2f5bf6
Expert discussion
No published comments yet. If you study palynology or mycology, we'd value your read on this specimen.