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30-07-2025 20:52

Bohan Jia

Hi together,  I've been looking posts in AscoFra

30-07-2025 18:06

Stefan Jakobsson

On a decorticated twig of Alnus incana on moist so

30-07-2025 10:12

Bernard CLESSE Bernard CLESSE

Bonjour à toutes et tous,Pourriez-vous m'aider à

29-07-2025 18:59

Castillo Joseba Castillo Joseba

Me mandan el  material seco de Galicia, España,

28-07-2025 12:34

Enrique Rubio Enrique Rubio

Hi to everybody.I would appreciate any ideas about

28-07-2025 04:59

Richard Droker

Growing on resin (over moss on Tsuga heterophyll)l

13-06-2025 09:41

Josep Torres Josep Torres

Hello.A cerebriform ascomycete sprouting scattered

13-06-2025 16:34

Andgelo Mombert Andgelo Mombert

Bonjour,Un petit discomycète qui me résiste. Il

24-07-2025 19:02

Castillo Joseba Castillo Joseba

De esta mañana en tronco caido de Haya A ver si

21-07-2025 19:22

Ethan Crenson

Hello all,  Here is an Orbilia found by a friend

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Asci with 4 spores
Jennifer Fiorentino, 01-12-2020 15:59
If an ascomycete typically produces 4 spores in each ascus does this mean that division stops at the 4-cell stage or that maybe after the 4th division which should give a final eight spores one of two spores aborts? I am examining a lichenicolous species of Pyrenidium and after many attempts found an ascus with 4 mature, brown spores. This is important for its ID. However when observing numerous asci in the process of development I am given the impression that 8 spores are developing. Each spore is finally tri-septate and so the 4 cell lumina might be contributing to my interpretation of counting 8 spores..
  • message #66281
  • message #66281
Franz Berger, 01-12-2020 17:16
Franz Berger
Re : Asci with 4 spores
To possibilities:
First: 4 of 8 ascospores are vanishing in course of maturisation, in this case, You could find normally also asci with 6  or 8 spores.

SEcond: nature has provided only 4 spores, which is the case in Pyrnidium actinellum  and is not bound to the number of septa ! You will find this also in spores with 2 septa also, but normality are 8/ ascus.. 
In lichens there are also examples with 1, 2, 4,  8, 16, 32, 64, .../ ascus; e.g. Pertsuaria has some species with only 1 spore, which has no septum.. 

Jennifer Fiorentino, 01-12-2020 20:03
Re : Asci with 4 spores
Many thanks for your input. I did identiify my lichenicolous fungus as P. actinellum based on the final 4 spores in the ascus as well as on presence of 3-septate spores and their size.. So if I understood your first statement correctly the development does not stop at the 4 spore stage but may go on and eventually "extra" spores do not mature further so ascus remains with its 4.
I agree with your second statement where you say that there is no connection between spore number and number of septa in each spore.
Thanks.