Unknown a-trifida-leaf-spot
The inducer of this gall is unknown or undescribed.
Hosts: Ambrosia trifida
Detachable: integral
Color: green
Texture: hairless
Abundance:
Shape:
Season: Spring
Related:
Alignment: integral
Walls: thin
Location: upper leaf, between leaf veins
Form: leaf blister, leaf spot
Cells:
Possible Range:i
Common Name(s):
Synonymy: 
Our ID Notes may contain important tips necessary for distinguishing this gall from similar galls and/or important information about the taxonomic status of this gall inducer.
Gallformers ID Notes
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Circular raised blisters on Ambrosia trifida. May be caused by some kind of rust fungus, cf Albugo tragopogi or Puccinia xanthii. Observed in Texas in May.
Possibly Protomyces:
- Underside of spots looks very like Taphrina, but Taphrina is not known for infecting Asteraceae. Protomyces is related to Taphrina and causes similar symptoms.
- P. gravidus causes large stem galls on A. trifida in Ark. and La. See Cartwright RD, Templeton GE (1988) Biological limitations of Protomyces gravidus as a mycoherbicide for giant ragweed, Ambrosia trifida. Plant Disease 72:580-582. doi.org/10.1094/PD-72-0580
- Gallformers Contributors: (2024) Gallformers ID Notes©
Further Information:
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See Also:
Unless noted otherwise in the ID Notes, observations of this gall are collected in the Observation Field Gallformers Code with value a-trifida-leaf-spot on iNaturalist. You can view them here:
