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29-11-2024 21:47

Yanick BOULANGER

BonjourJ'avais un deuxième échantillon moins mat

27-02-2026 17:51

Michel Hairaud Michel Hairaud

Bonjour, Quelqu'un peut il me donner un conseil p

27-02-2026 16:17

Mathias Hass Mathias Hass

Hi, Found this on Betula, rather fresh fallen twi

27-02-2026 12:56

Åge Oterhals

Found on fallen cones of Pinus sylvestris in midle

27-02-2026 11:21

Yannick Mourgues Yannick Mourgues

Hi to all. Here is a specie that can may be relat

26-02-2026 22:06

Malcolm  Greaves Malcolm Greaves

Can someone explain the features that split Geoscy

26-02-2026 15:00

Castillo Joseba Castillo Joseba

Me mandan el material seco de Galicia, recolectada

24-02-2026 00:21

Benoît Segerer

Hello,I'm new to this forum, I hope I won't be irr

24-02-2026 11:01

Gernot Friebes

Hi,found on a branch of Tilia, with conidia measur

23-02-2026 11:22

Thomas Læssøe

https://svampe.databasen.org/observations/10584971

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Coryneum (?) acervuli on oak (?) branch
Ethan Crenson, 12-01-2026 22:02
Hello all,

I am hoping someone will have some insight into this interesting asexual fungus I found on hardwood (probably oak) in a New York City park yesterday. It appears to be erumpent, gelatinous acervuli which bristle with conidia on the surface. When cut the solid interior of the acervuli are black (when fresh) and gelatinous. As they age and hollow out they become tan.


The conidia are brown, very thick walled, multi-septate, and shaped like bowling pins. Sometimes they are curved. There are wavy striations in the flanks of the conidiospores. I am reminded of the conidiospores of Helminthosporium velutinum, but of course that does not produce acervuli like this.


I have seen some discussion/images of the genus Coryneum which seems similar. Can anyone point me in the right direction?


Thanks!
Ethan

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Mathias Hass, 13-01-2026 08:01
Mathias Hass
Re : Coryneum (?) acervuli on oak (?) branch
Hi Ethan

I agree with Coryneum (or teleomorph name Pseudovalsa). There are several species on oak. The dimensions of the conidia might be helpful.

Cheers Mathias
Ethan Crenson, 13-01-2026 21:06
Re : Coryneum (?) acervuli on oak (?) branch
Mathias, 

Thanks for the confirmation on genus.  I guess I did forget to include conidia measurements.  

The larger spores (I excluded the "stunted" looking ones) measure:

76.7-101.9 x 15.3-21.1µm

Me: 91.4 x 18.2µm

Q: 4.4-5.4

Qe: 5

N=9

I have counted from 7 to 11 distosepta in the conidia that I have illustrated here.

I found a key in J. Muthumary; B.C. Sutton. (1986). Coryneum quercinum sp.nov. on Quercus alba from India. , 86(3), 0–515. The key treats Coryneum on Quercus only, so I hope that my ID of the substrate is correct.  

I am unable to see the conidiophores (I am assuming I would need a microtome to section the gelatinous material properly).  But I feel I can exclude C. quercinum based on dimensions of the conidia.  Which leaves the next option at C. megaspermum var. megaspermum "Conidia with up to 11 distosepta, 76-100 x 12-15." The conidia in my collection are somewhat wider. Continuing in the key I get to C. neesii, but the length and number of distosepta doesn't match. 

So I'm left with perhaps C. megaspermum var. megaspermum with conidia somewhat too wide. 

Or maybe I have the wrong substrate.

Ethan
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