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on small deciduous twig on the ground in forest wi
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Bernard CLESSE
Bonjour à toutes et tous,Pourriez-vous me donner
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Lothar Krieglsteiner
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Phomatospora on Urtica
Chris Yeates,
04-10-2017 22:38
Bonsoir tousI recently collected some Urtica stems at the edge of a dense "jungle" of Rubus idaeus which I have been studying regularly for several years. Careful examination under the stereo microscope revealed a Phomatospora species. Under oil immersion it was clear that the spores had wavy, longitudinally striate walls.
Looking at the key to North American Phomatospora spp. in Margaret Barr's paper in Mycotaxon 51 p.217 she indicates two species with longitudinally striate spores: P. berkeleyi and P. striatispora. The spores of my collection are too small for the former and to my mind rather the wrong shape, nor do any have the "pulvinate terminal appendages" which Barr talks of.
Accordingly I am inclined to call this Phomatospora striatispora, although the spores are towards the bottom range of Barr's measurements (which she admits were based solely on the type collection). Alick Henrici has collected this from Kew Gardens, again on Urtica; as far as I know this is the only previous UK collection.
If anyone knows Phomatospora striatispora or has any comments to make I would be grateful. (The PDF will zoom up to at least 300% without pixellation)
Cordialement
Chris
Phomatospora-striatispora-0a-0001.pdf
Jacques Fournier,
05-10-2017 09:59
Re : Phomatospora on Urtica
Bonjour Chris,
118 species of Phomatospora are listed in Index Fungorum. They typically have longitudinally striate ascospores. Some are dubious, most are poorly documented, thus it's not an easy task. The only species occurring on Urtica I am aware of is Phomatospora feurichiana Kirschst., collected in Switzerland. Its ascospores are 8-11 x 3-3.5 µm, a bit small for you, sorry.
Good luck!
Jacques
118 species of Phomatospora are listed in Index Fungorum. They typically have longitudinally striate ascospores. Some are dubious, most are poorly documented, thus it's not an easy task. The only species occurring on Urtica I am aware of is Phomatospora feurichiana Kirschst., collected in Switzerland. Its ascospores are 8-11 x 3-3.5 µm, a bit small for you, sorry.
Good luck!
Jacques
Bernard Declercq,
06-10-2017 14:34
Re : Phomatospora on Urtica
Bonjour Jacques,
Nous avons des collections de P. berkeley sur Urtica ici en Belgique. Mais la détermination est peut-être fautive. Comment faire la différence entre P. berkeley et P. feurichiana?
Merci d'avance pour ton aide.
Bernard
Nous avons des collections de P. berkeley sur Urtica ici en Belgique. Mais la détermination est peut-être fautive. Comment faire la différence entre P. berkeley et P. feurichiana?
Merci d'avance pour ton aide.
Bernard
Chris Yeates,
07-10-2017 02:19
Re : Phomatospora on Urtica
Like Bernard, in the UK (as well as records of P. dinemasporium, both anamorph and teleomorph) we have quite a few P. berkeleyi records on Urtica:
http://www.fieldmycology.net/FRDBI/FRDBIrecord.asp?strAssoc=Urtica&strName=Phomatospora+berkeleyi
http://www.fieldmycology.net/FRDBI/FRDBIrecord.asp?strAssoc=Urtica&strName=Phomatospora+berkeleyi
Chris
Jacques Fournier,
07-10-2017 19:19
Re : Phomatospora on Urtica
Hi Chris,
you made it clear that a Phomatospora referred to P. berkeleyi is frequently collected on Urtica. The point is that there is some confusion about the delimitation of P. berkeleyi.
Spores dimensions are not given in the protologue of Sphaeria phomatospora, Saccardo gives 6-8 x 2-2.5 µm for P. berkeleyi, without mention of appendages. To follow Barr's concept, spores are 7-10.5 x 2.5-3.5 µm, with appendages.
This involved several different interpretations of P. berkeleyi and I think this name should be used with reservations until the type material is revised. Host specificity is often suggested in Phomatospora but difficult to assess when identification of species is confused.
The type collection is from UK, on potatoe stems in March, thus maybe you can solve the problem by finding a fresh collection of this fungus!
Best,
Jacques
you made it clear that a Phomatospora referred to P. berkeleyi is frequently collected on Urtica. The point is that there is some confusion about the delimitation of P. berkeleyi.
Spores dimensions are not given in the protologue of Sphaeria phomatospora, Saccardo gives 6-8 x 2-2.5 µm for P. berkeleyi, without mention of appendages. To follow Barr's concept, spores are 7-10.5 x 2.5-3.5 µm, with appendages.
This involved several different interpretations of P. berkeleyi and I think this name should be used with reservations until the type material is revised. Host specificity is often suggested in Phomatospora but difficult to assess when identification of species is confused.
The type collection is from UK, on potatoe stems in March, thus maybe you can solve the problem by finding a fresh collection of this fungus!
Best,
Jacques