04-11-2025 09:07
Josep Torres
Hello.A suspected Hymenoscyphus sprouting on a thi
04-11-2025 12:43
Edvin Johannesen
Hi! One more found on old Populus tremula log in O
03-11-2025 21:34
Edvin Johannesen
These tiny (0.4-0.5 mm diam.), whitish, short-stip
28-10-2025 15:37
Carl FarmerI'd be grateful for any suggestions for this strik
03-11-2025 16:30
Hans-Otto Baral
Hello I want to ask you if you have found this ye
Hymenoscyphus aesculi
Chris Yeates,
02-09-2020 19:12
Bonsoir tous
Following on from a previous thread: http://www.ascofrance.com/search_forum/19553 in the same locality (and interestingly also in August) I made a fresh collection of this species, on petioles and leaf-veins of Aesculus hippocastanum. Now, with the advantage of better optical equipment it seems a good idea to add some images, and in the hope that others might look out for this species which seems to favour damp periods in late summer on this host.
What can be seen is the characteristically-shaped spores commented upon by Zotto in the previous thread - in one case (image included) the spores were seen to have formed an elegant spiral within the ascus. Asci have typical Hymenoscyphus-like IKI+ apical apparatuses and no croziers. The paraphyses in this collection showed well the VBs in various stages of development.
Of particular interest was the presence, in one of the large apothecia from a petiole, of obvious crystals in the blackened stem-base - mostly small, but the large conglomerated one in the final photograph measured 20µm at its widest dimension. In the description of Hy. aesculi the absence of crystals is stressed, so they perhaps should be viewed as extremely rare.
Cordialement
Chris
Hans-Otto Baral,
02-09-2020 20:53
Re : Hymenoscyphus aesculi
Bonsoir Chris
great pics!
There are in the meantime 5 sequences from very different arreas, and all concur well.
About crystals: Never seen them here. What would be good is to make a section of the stem base to see if they are inside the medulla or not. This is not difficult, one must cut the stem somewhat above its base and then with a razor blade under the bino a vertical section. Perhaps also a cross section through the stem would work.+
Amicalement
Zotto