
21-01-2007 21:00
Javier OrmadApotecios sesiles o subsesiles, disciformes, pulvi

20-01-2007 19:38

Queridos amigos pido ayuda para la determinación

20-01-2007 13:23
Dmitry GavryushinJan. 07, 2007, on small dead branches of Alnus and

20-01-2007 13:19
Dmitry GavryushinJan. 07, 2007, on a broken and split trunk of a yo

20-01-2007 13:14
Dmitry GavryushinJan. 14, 2007, on fallen catkins of Salix. Size 0.
Ascobolus puzzle
Chris Yeates,
03-12-2021 15:29

An Ascobolus sp. has appeared in some quantity on dung of Canada Goose, Branta canadensis.
The apothecia are whitish, globose and very small (0.25-0.3mm) and would presumably be placed in section Dasyobolus. Asci are 8-spored; the ascospores measure 29-31.1 x 15.5-17.6µm. It is the ornamentation of the ascospores which has me confused. The pigmented epispore is not smooth, or warted or with a pattern of elongated cracks, instead the surface of the spores is covered with numerous, small irregular pits (De: "Gruben" / Fr. "fosses") as can be seen in these preliminary images. The ornamentation is not total in many spores and there are are paler areas; on seeing this at lower magnifications I wondered about A. degluptus, but all the images of that I have seen show a warted ornamentation. There are occasional irregular cracks on some of the spores - these can be seen in the images here.
I know A. stictoideus well and it is not that - I also place here an image of that species using the same microscopy to show the difference.
I cannot find any Ascobolus species which match this find - any thoughts would be very welcome. More images will follow.
Cordialement
Chris
Michel Delpont,
03-12-2021 17:14

Re : Ascobolus puzzle
Good evening Chris!
Indeed your spore measurements are a bit large for stictoideus, but otherwise I find that they look good for this species. Degluptus is different for ornamentation and does not match in my opinion.
Michel.
Chris Yeates,
04-12-2021 16:13

Re : Ascobolus puzzle
Many thanks Michel
I agree about the measurements being reasonable for A. stictoideus and that this is clearly not A. degluptus. But the spore ornamentation seems very different from both - perhaps you have seen similar? Also the ascus wall did not turn blue with IKI (Baralsche Löhsung).
I shall make some more preparations.
Chris