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10-03-2026 18:08

Marc Detollenaere Marc Detollenaere

Dear Forum,On stems of Arctium, I found some downy

05-03-2026 10:07

Hulda Caroline Holte

Hello, I found and collected this species growing

07-03-2026 13:06

éric ROMERO éric ROMERO

Bonjour tous, Sur cône d'épicea fortement imbu,

23-12-2025 08:27

Josep Torres Josep Torres

Hello.Small, yellowish ascomata, with very short a

28-02-2026 11:05

Yanick BOULANGER

Bonjour à tousLe 24/02/2026 à Montmacq, devant m

08-03-2026 14:05

Thierry Blondelle Thierry Blondelle

Bonjour à tous,Sur 3 récoltes supposées de H. l

07-03-2026 22:22

Josep Torres Josep Torres

Hello.Some very tiny conidiomes collected in the D

06-03-2026 17:51

William Slosse William Slosse

Good evening all,On March 4, 2026, I found the fol

05-03-2026 16:30

François Bartholomeeusen

Dear forum members, On the 2nd of February 2026,

06-03-2026 09:41

Alain GARDIENNET Alain GARDIENNET

Hi forum, I'm now looking for another reference c

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Leptosphaeria?
Josep Torres, 04-11-2025 14:53
Josep TorresHello.
Very small, globose, mucronate perithecia, blackish in color and very uniform in size, between 0.25 and 0.30 mm in diameter, sprouting sporadically from a dry herbaceous stem still attached to the plant.
Hyphae of the perithecium wall, globose angular in texture, with an intracellular brown pigment.
Hyphae of the excipulum globose and hyaline, from which arise paraphyses with swellings and short septa.
Asci apparently eight-spored, with no reaction to Melzer's reagent in their apical apparatus. Fusiform, hyaline ascospores with 2 to 4 septa, no reaction with Melzer's reagent, and with the following measurements of free spores:
(28.9) 30.4 - 42.4 (43) × (3.9) 4.5 - 6.3 (6.7) µm
Q = (5.3) 6 - 7.4 (8.5) ; N = 12
Me = 35.8 × 5.4 µm ; Qe = 6.7
Based on the microscopic data obtained, the closest match I know would be Ophiobolus sp., but I admit I'm not entirely sure.
Any suggestions would be greatly appreciated.
Thank you in advance.
Best regards.
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Josep Torres, 06-11-2025 09:25
Josep Torres
Re : Leptosphaeria?
Hello.
It seems the issue isn't with Ophiobolus, and it's most likely a Leptosphaeria, perhaps even, but only perhaps, Leptosphaeria maculans, something I can't confirm since the ascomata were already in poor condition.
http://www.ascofrance.com/search_recolte/3097
I'll edit the post.
Best regards.
Mathias Hass, 08-11-2025 12:20
Mathias Hass
Re : Leptosphaeria?
Hi Josep,

I doubt its L. maculans, which should have 5-septate spores at least when fully developed and the firstformed septum (the one with the strongest constriction) should be the 3rd septum fom the top in the fully formed spore, and in you spores it seems to be the second septum. Finaly your sporemeasures are on the short side for L. maculans.  If genuinely 4-septate that would narrow possibilities down (althoug there seems to be one 5-septate spore in one of your asci, could be an exception). Nodulosphaeria modesta might be a possibilty, but probably more fresh material is needed.

Kind regards Mathias
Josep Torres, 08-11-2025 15:42
Josep Torres
Re : Leptosphaeria?
Thanks Mathias, you're right. I'll try to get more fresh specimens. For now, I'll leave this study as Nodulosphaeria cf. modesta = Leptosphaeria cf. modesta.

Best regards