Observation 203979: Miriquidica deusta (Stenh.) Hertel & Rambold

When: 2015-05-01

Collection location: Serra de São Mamede, Portugal [Click for map]

Who: zaca

No specimen available

See the Notes of observation 203977.
As the second of the non-yellow species of Rhizocarpon I chose one that revealed to be very common here but that up to now I didn´t found fertile. This time I found some fertile specimens, like the one posted here, that I hope will permit to confirm microscopically the presumed name: R. bolanderi.


Sp. 1
Non-yellow specimens of Rhizocarpon found.
Sp. 2 – Other similar specimen;
Sp. 2 – Apothecial section (of the specimen in the previous photo).
Sp. 3 – Living at the same rock than Sp. 1;
Sp.3 – close up;
Microscopy: Sp. 3 – Sections;
Microscopy: Sp. 3 – Asci and spores.

Proposed Names

29% (1)
Recognized by sight
58% (1)
Eye3 Eyes3
Used references: See the comments
Based on microscopic features

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Rhizocarpon definitely ruled out; Miriquidica stand up !
By: zaca
2015-09-23 07:37:06 CDT (-0400)

The main problem faced was the poor samples I could get; in the absence of adequate tools, I collect the material using a knife to scrape the rock.
I attached already photos of another specimen (for convenience I numbered the specimens in the attached photos) for which I was able to find some (though few) spores, which are simple, hialine and have the following dimensions:
13.2 – 15.1 × 5.4 – 6.1 µm;
Q = 2.4 – 2.6 ; N = 9; Me = 14.2 × 5.7 µm ; Qe = 2.5.
This is another point in favor of Miriquidica deusta, whose spores are just like that, according to Ref. 2 in my previous comment, and definitely shows that the species in consideration is not a Rhizocarpon (as I thought initially).

Some information on Miriquidica deusta.
By: zaca
2015-09-20 09:34:06 CDT (-0400)

It seems that I have to change the name of all my observation previously classified as Rhizocarpon bolanderi. In fact, that name appeared to me in 2011 due to the similarity of one of my specimens and that species as illustrated in Ref. 1. That similarity is not a full match, because the squamulas in my specimens always are very irregular, almost stellate in some cases and upturned at margins, whereas the squamulas of R. bolanderi are much smoother. It happens that all my specimens were infertile, except this one and others collected at the same zone (like the one whose photo I attach now with label “Other similar specimen”), for which I was not able to find spores (maybe due to youth) but succeded to make an apothecial section (see the photo “Apothecial section”). Looking to it one can see that most probably it doesn’t belong to any Rhizocarpon sp..
This problem made me search again for other similar lichens in the internet. Recently, I found something very similar classified as Miriquidica deusta in one of the references below and after that I found several other references (I include below a list). One of those references (Ref. 2) also includes a small description, referring in particular:
“Thallus crustose, tightly appressed to the substratum, areolate, areoles squamulose, 0.5-1.5 mm, more or less scattered on a conspicuous black prothallus, surface smooth and bright, edges irregular more or less crenulate and upturned, dark brown, brown-blackish, blackish, margin greyish, prothallus large, blackish to black, limits indistincly defined. Not fertile in our prospection area, elsewhere apothecia immersed in the thallus at first, then slightly prominent …”
“This species preferentially seems to develop nearby yellow Rhizocarpon sp., similarly to Miriquidica intrudens which is parasite of yellow Rhizocarpons sp. but also nearby Lecidea fuscoatra. When young, might have a parasite stage”.
Therefore, it seems to me that all my specimens fit very well in this description and habitat, and consequently I propose to change the name accordingly.

Ref. 1: http://nhm2.uio.no/...
Ref. 2: http://www.lichensmaritimes.org/...
Ref. 3: http://www.stridvall.se/lichens/gallery/Miriquidica/D80A5594
Ref. 4: http://dbiodbs.univ.trieste.it/...
Ref. 5: http://www2.ac-lille.fr/...
Ref. 6: http://www.bgbm.org/...

Created: 2015-05-06 18:36:24 CDT (-0400)
Last modified: 2015-09-23 07:32:21 CDT (-0400)
Viewed: 68 times, last viewed: 2018-04-06 12:10:53 CDT (-0400)
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