26-11-2025 18:13
Jason Karakehian
The entire run of Mycotaxon is now available throu
25-11-2025 14:24
Thomas Læssøehttps://svampe.databasen.org/observations/10490522
25-11-2025 11:03
Mick PeerdemanHi all,One of my earliest microscopy attempts, so
24-11-2025 15:23
Arnold BüschlenHallo, auf einer offenen Kiesfläche am Rande ein
23-11-2025 11:16
Bohan JiaHi, I found small discs growing on dead stem of
21-11-2025 10:56
Christopher Engelhardt
Very small (~0,5 mm) white ascos, found yesterday
Found on a fallen branch of oak. The wood is colored black and the stromata has a stipe of 8x1 mm and a fertile part of 11x2.5 mm. The outer crust is hard and black with grey patches and lumpy as a result of the underlying perithecia.
TELEMORPHE:
Perithecia: subglobose 514 x 400 µm
Asci: cylindrical 124-158 x 8-9,65 µm
Paraphyses: filiform
Spores: 11,35-13,37 x 5,14-5,94 µm Q= 2.23 with straight germsplit (spore lenght 11.2 µm with germsplit length 7.85 µm)
ANAMORPHE: flat length 5-8 mm; conidia:10,41-16,3 x 3,02-3,86 µm
Macroscopic/microscopic this frb looks like Xylaria arbusula except the length of the asci is wrong and I found it in Belgium/Turnhout in winter! Is this not a tropical asco?
I will be grateful for your help!
Greetings,
François Bartholomeeusen
your images do not allow an identification.
Before considering X. arbuscula you should rule out X. hypoxylon. The key feature distinguish them is the thickness and texture of the outer crust. See my notes in the monographic keys available on Ascofrance.
Good luck,
Jacques
I have made the wrong choice at step 2 of your superb key. I chose "Stromata hard-textured with a carbonaceous outer crust".
Perhaps the persistent, drying east wind, the sun and the freezing temperature changed the texture a bit? In all cases reading your notes has shed light on my problems. I have also measured the out crust and is was about 40-45 µm thick.
Thank you for your quick reaction!
Cordial greetings,
François