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When: 2016-06-10

Collection location: New Hope Pines State Natural Area, Wisconsin, USA [Click for map]

Who: Andrew Khitsun (Andrew)

No specimen available


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Yes, it appears the same, at least it’s the same genus for sure (and not Ribes)
By: Andrew Khitsun (Andrew)
2016-06-11 14:08:32 MST (-0700)

I wasn’t aware of any potential competitors to the two species in question, so didn’t dwell on trying to ID the host plant to species. Will try to do next time, although the specimen I came across so far were very small/somewhat wilted, not having flowers or berries or other prominent traits to ID to species. Being small (young?) they didn’t even have thorns – useful ID trait.

Is the host plant the same?
By: Byrain
2016-06-11 10:13:20 MST (-0700)

Otherwise the other observation is not that helpful unfortunately. There are countless examples of similar looking rusts that differ only by their host, this is not including those nightmare genera like Phragmidium (Rose rusts) that require teliospores or maybe even access to an electron microscope and DNA sequencing before you can have a hope of identifying them…

Both Arthuriomyces peckianus and Gymnoconia nitens are species that infect Rubus (Raspberry, blackberry, dewberry) in the family Rosaceae. While Ribes (Gooseberry) are in the family Grossulariaceae and will have different rust species.

So are these infecting Rubus? Ribes? Something else?

Other rust taxa listed by Arthur on Rubus include:

Pucciniastrum americanum (Uredia and telia, pycnia and aecia on Picea canadensis)
Pucciniastrum arcticum (Uredia and telia, pycnia and aecia on Picea canadensis)
Phragmidium rubi-idaei
Phragmidium rubi-odorati
Phragmidium occidentale
Phragmidium alaskanum
Kuehneola uredinis
Mainsia epiphylla

Ribes also has numerous taxa listed for it…knowing exactly what plant species will undoubtedly help a lot.

If it helps, I can point at this discussion:
By: Andrew Khitsun (Andrew)
2016-06-10 23:17:49 MST (-0700)
By: Byrain
2016-06-10 22:44:01 MST (-0700)

With rust fungi and even plant pathogens in general most species are highly specific on the host plant family, genus or species. For best identifications the host plant should be identified first, without knowing what the host is putting a name on any rust fungus is rather immature.

Unfortunately I won’t be much help with identifying plants in Wisconsin…

Can’t figure out.
By: Andrew Khitsun (Andrew)
2016-06-10 20:31:24 MST (-0700)

Very small plants, most affected by fungus. Intermixed with Gooseberry that can be seen in photos too. Does the species of host in this case determine the species of fungus?

By: Byrain
2016-06-10 20:19:23 MST (-0700)