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Observation 93448: Arrhenia Fr.

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By: S. Redhead (Scott)
2014-04-03 14:03:55 SAST (+0200)

Oh – that is rather interesting. We should look harder to see if they are attached and whether the Arrhenia forms them or whether a parasite forms them. The observations are on page 142 for species number 139 for A. spathulata, but it is hard to tell from their photograph if it is A. spathulata or A. retiruga. They show what look like chlamydospores forming inside the spinde-shaped “conidia”.

Congratulations also on the transfer of specimens to UBC.

Arrhenia & conidia
By: Oluna & Adolf Ceska (
2014-04-02 20:30:49 SAST (+0200)

The presence of conidia in Arrhenia spathulata has been already mentioned in
Breitenbach, J., & Kränzlin, F. (1991). Fungi of Switzerland Volume 3 Boletes and Agarics First Part. See page 139: “We could find no reference anywhere in the literature to the conidia occurring in nests in the pileipellis. Since we could not find any conidiophores, we do not know their origin, and it is not certain whether they belong to this fungus or not (observed in several collections).”

Redhead, Lutzoni, Moncalvo & Vilgalys broadened the original concept of Arrhenia to include non-lichenized Omphalina species. If you accept this broader concept, the difference between Arrhenia spathulata and Arrhenia retiruga is negligible, especially to non-mycologists (e.g., Adolf). That was already discussed in Redhead, S.A. (1984): Arrhenia and Rimbachia, expanded generic concepts, and a reevaluation of Leptoglossum with emphasis on muscicolous North American taxa. Canadian journal of botany 62(5): 865-892.

Arrhenia retiruga
By: S. Redhead (Scott)
2014-04-02 18:23:47 SAST (+0200)

This looks more like Arrhenia retiruga which is found in western North America. However, the condia are either not related to it or are totally new observations. I suspect they are contaminating it. Please provide more details on the conidia.

By: Irene Andersson (irenea)
2012-04-28 18:23:07 SAST (+0200)

with the conidia! Those are not mentioned in any keys I have seen.

I notice that “Swiss p. 142” only deals with spathulata (not mentioning retiruga). Their picture actually looks more like retiruga than spathulata too.

I can see that Andreas Gminder has studied these species, let’s hope that he chimes in..

Have you considered
By: Irene Andersson (irenea)
2012-04-28 11:01:23 SAST (+0200)

any other species?
My first impression was Arrhenia retiruga (very pale and cupshaped with dorsal attachment). Not sure about other possibilities, but I don’t recognize this as spathulata. Unfortunately, microscopy doesn’t help to tell those two apart.