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
                                    28-10-2025 19:33
                Nicolas Suberbielle
                Bonjour à tous,Je voudrais votre avis sur cette r
                                    31-10-2025 09:19
                Lothar Krieglsteiner
                Can somebody provide me with a file of:Rogerson CT
                                    09-08-2025 13:13
                Maria Plekkenpol
                Hello,Yesterday I found these on burnt soil. Apoth
Acanthostigmella
    
                    Eduard Osieck,
                23-04-2015 20:19
    
    Minute hyaline perithecia (0.05-0.06 mm) with hyaline setae (20-23 um).
Bitunicate asci (30-40 x 10 mu) with 3-septate hyaline spores with big guttules: 13-16 x 4-5 um. One median cell larger than the other.
Substrate: Lophiotrema cf. neohysterioides (= curreyi) and on bark of Hedera.
I assume this belongs to the genus Acanthostigmella.
With the key included in the paper of Barr 1977 it easily keys out as A. pallida but this species has much smaller spores (7-10 X 2.5-3.5 um) and smaller ascii (20-25 x 10-11 um).
Six years later (Barr & Rogerson 1983) described A. brevispina (also known as Tubeufia brevispina) as a new species with spores which are more in agreement with my find: 14-18 x 4-5 um. However this species has larger ascii (50-60 mu) and also much larger perithecia (diameter 0.13-0.18 mm).
Belongs this find to Acanthostigmella? And what about the species?
I hope somebody has some knowledge about this species although the Ascofrance database does not contain any finds.
Eduard
                                    Björn Wergen,
                                01-05-2015 00:01            
            
                Re : Acanthostigmella
                Hi Eduard,
do you still have a piece of this collection for studying?
regards,
björn
                
                
                
                
                
                            do you still have a piece of this collection for studying?
regards,
björn
                                    Eduard Osieck,
                                01-05-2015 15:23            
            Re: Acanthostigmella
                Hi Björn,
Yes the material is still in good condition, the perithecia have even multiplied over a larger area of the (not dead) Hedera twig. Apparently the ascomata become pale brownish after some time. Some ascomata are larger than indicated, up to 0,10 mm, but still smaller than in Barr's description of A. brevispina. However, I have found also much longer ascii, up to 64-75 um. They seem to stretch outside the perithecia. So it might very well be this species or a yet undescribed European counterpart. Particularly striking is the enlarged median cell ("2e loge sporale nettement renflee", quoted from Holm 1957).
I will send you the material today, than we get at least splendid photos :)
EDuard
                
                
                
                
                
                            Yes the material is still in good condition, the perithecia have even multiplied over a larger area of the (not dead) Hedera twig. Apparently the ascomata become pale brownish after some time. Some ascomata are larger than indicated, up to 0,10 mm, but still smaller than in Barr's description of A. brevispina. However, I have found also much longer ascii, up to 64-75 um. They seem to stretch outside the perithecia. So it might very well be this species or a yet undescribed European counterpart. Particularly striking is the enlarged median cell ("2e loge sporale nettement renflee", quoted from Holm 1957).
I will send you the material today, than we get at least splendid photos :)
EDuard
                




