Psammina filamentosa on Punctelia?

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JennyS
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Posts: 217
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Psammina filamentosa on Punctelia?

Post by JennyS »

Very faint brown marks on lobe of Punctelia borreri on Dorset/Wiltshire border. Under the microscope the conidial arms were c.50-75 µm long, straight and very slightly tapered at the ends - is this Psammina filamentosa?
Psammina filamentosa q 240515 015.jpg
Psammina filamentosa q 240515 021.jpg
Psammina filamentosa q 240515-1.jpg
Some smaller clumps in the same section had conidial arms slightly more curved and much shorter, most <30 µm long - are these immature or possibly a different species?
Psammina q1 240515 019.jpg
Psammina q1 240515-1.jpg
Jenny Seawright
Paul Cannon
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Re: Psammina filamentosa on Punctelia?

Post by Paul Cannon »

Could well be, but difficult to be sure from your images. The conidial arms are supposed to be 2.5-4 um diam. and multiseptate - is that the case with your collection? Another option would be an Epithamnolia, but that doesn't seem to fit macroscopically.

Best wishes
Paul
JennyS
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Re: Psammina filamentosa on Punctelia?

Post by JennyS »

Thanks Paul - the arms were 2.5-3.5 µm wide and with septa present, but not clear enough to count how many. I emailed David Hawksworth a few days ago but haven't had a reply yet.
w Psammina filamentosa q 240515-1b.jpg
Jenny Seawright
JennyS
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Posts: 217
Joined: Wed May 13, 2015 6:08 pm

Re: Psammina filamentosa on Punctelia?

Post by JennyS »

The conidia with long arms confirmed by David Hawksworth as Psammina filamentosa.
Jenny Seawright
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