Very odd Xanthoria

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JennyS
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Very odd Xanthoria

Post by JennyS » Thu Jan 23, 2020 9:05 pm

A Xanthoria from Dorset yesterday in the axil of a shaded Birch twig, no rhizines but (among the lower side grot) very occasional hapters. X. polycarpa seems closest but substrate too acidic and the thallus is very nodulose with few apothecia.

Thoughts and comments appreciated as I'm hanging onto the specimen and just calling it Xanthoria sp. for now!
Xanthoria 200122 031.jpg
Xanthoria 200122 034.jpg
Xanthoria 00122 032.jpg
Last edited by JennyS on Fri Jan 24, 2020 8:45 pm, edited 1 time in total.
Jenny Seawright

Fay Newbery
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Re: Very odd Xanthoria

Post by Fay Newbery » Fri Jan 24, 2020 10:54 am

It certainly is odd. The apothecia don't seem to be particularly stalked.

Neil Sanderson
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Re: Very odd Xanthoria

Post by Neil Sanderson » Fri Jan 24, 2020 11:53 am

What about Xanthoria calcicola? Looks like the coarse globose isidia of this species on the thallus surface. LGBI 2 says:
Lowlands, especially on calcareous, nutrient-rich stonework, brickwork, tiles, monuments, rare on bark and wood
I have never seen it on bark, but it seems it can grow in this habitat

Neil
Neil Sanderson

JennyS
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Re: Very odd Xanthoria

Post by JennyS » Fri Jan 24, 2020 8:22 pm

Thanks for the suggestion Neil - but wouldn't Birch twigs be too acidic a substrate and surely the outer lobes are wrong for a corticolous X. calcicola?
Forgot to mention in first post but the thallus is only 1.5 cm

zz Xanthoria 200122 031.jpg
zz Xanthoria 200122 034.jpg
Jenny Seawright

Neil Sanderson
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Re: Very odd Xanthoria

Post by Neil Sanderson » Fri Jan 24, 2020 9:11 pm

Xanthoria calcicola is not a strongly held option, but it would, I suppose be stunted growing on a Birch! Seems like the classic young Cladonia problem; too small/under developed to be identifiable. Otherwise out of ideas.

Neil
Neil Sanderson

Glos lichens
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Re: Very odd Xanthoria

Post by Glos lichens » Mon Apr 13, 2020 11:35 am

I wasn't sure whether to post this at all, but given Mark Powell's comment elsewhere on this site that Xanthoria polycarpa is a species "gone out of fashion" and several discussions I've had recently with people that either never see it or have trouble differentiating it from parietina, this seems the right time and place.
I come across what I believe is Xanthoria polycarpa quite often, particularly on urban twigs, but these are two recent rural finds, from birch in a garden in north Gloucestershire and an apricot tree in my garden in central Gloucestershire.
Attachments
Fruit can get large and obscure the thallus. On apricot.
Fruit can get large and obscure the thallus. On apricot.
Lateral view showing domed appearance. On apricot.
Lateral view showing domed appearance. On apricot.
Xanthoria polycarpa (yellow fruit on left) on birch twig with Lecidella elaeochroma and Lecanora chlarotera. This is a small species (unlike Xanthoria parietina) and this particular specimen is not as yellow as it often is. On birch. mm scale.
Xanthoria polycarpa (yellow fruit on left) on birch twig with Lecidella elaeochroma and Lecanora chlarotera. This is a small species (unlike Xanthoria parietina) and this particular specimen is not as yellow as it often is. On birch. mm scale.
Xanthoria polycarpa on apricot twig, centre, with fruiting Xanthoria parietina top right (and non-fruiting lobe of Xanthoria parietina far left) showing the difference in scale of the two lichens. On apricot.
Xanthoria polycarpa on apricot twig, centre, with fruiting Xanthoria parietina top right (and non-fruiting lobe of Xanthoria parietina far left) showing the difference in scale of the two lichens. On apricot.
Xanthoria polycarpa on apricot twig. The big yellow lobes towards the bottom right are of Xanthoria parietina; note its large round smooth edge, unlike the small nodular fingers of the X polycarpa. mm scale.
Xanthoria polycarpa on apricot twig. The big yellow lobes towards the bottom right are of Xanthoria parietina; note its large round smooth edge, unlike the small nodular fingers of the X polycarpa. mm scale.

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