Dear Ethan,

this looks interesting. Do you know from which host it was collected? Massaria species are highly host specific, so correct host identification is highly important and often crucial for identification. Acer should be quite clear - Massaria from the USA was most frequently collected from Acer saccharum and A. rubrum. The latter is confirmed host of Massaria vomitoria, but your spores are much too large for that species. Or did you collect it from an introduced European maple species (Acer platanoides)? Then it could be a European species.

Your measurements indicate that your specimen belongs to the Massaria inquinans group. We have three species here in Europe, which are on different maple hosts. It is likely that North American maple species harbour additional species from the M. inquinans group, but there are no investigations yet.

I would be interested to obtain the material in vital condition (air-dried to avoid moulding during mailing) for pure culture isolation and sequencing, then we could tell more about it.

Best regards,

Hermann

Dear Ethan,

thx. I sent you the address via pm.

Concerning the collection site, was it a forest, or a park etc. in an urban area?

Cheers, Hermann

I had a brief internet search on the flora of this park - the European Acer platanoides (Norway maple) is reported as naturalised from the park, but also the native Acer rubrum. So it would be good to identify the host species if possible.

Your measurements (spore length and esp. width) fit well Massaria platanoidea from European Acer platanoides, which could have been introduced to North America with its host. But cultures and sequences will finally tell...

Hermann