PollyMapHelminthosporium mold spore photographed through the microscope in the PollyKit lab — verified in Arizona.
More verified photos of Helminthosporium
About bipolaris / drechslera mold spores
Elongated, banded mold spores that grow on grasses and cereal leaves and rise into the air when turf is mowed or disturbed.
Where it grows
- Lawn and pasture grasses with leaf spot disease
- Corn, wheat and other cereal foliage
- Grass clippings and thatch
- Soil and plant debris
How to recognize it
Cylindrical to slightly curved brown spore divided by several straight crosswalls, often with a slightly darker scar at the point of attachment. Ends are usually rounded rather than pointed.
Typical published size: 30–100 µm long
Commonly confused with
- Curvularia — distinctly bent, with one swollen darker central cell
- Pleospora and Alternaria — additional lengthwise walls
Allergy relevance
Recognized mold allergens linked to allergic rhinitis, allergic fungal sinusitis and asthma symptoms; counts spike during mowing and dry windy conditions.
Where it's found
PollyMap has verified specimens of Helminthosporium from Arizona.
Common wherever turf or cereal crops grow, across the United States.
Also searched as: bipolaris spore, drechslera spore, helminthosporium spore, grass mold spore.
Related mold specimens
Citing this specimen: PollyMap Specimen Library. “Helminthosporium — verified microscope specimen.” pollymap.com/library/specimen/helminthosporium-mold-spore-ce601c
Expert discussion
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