Observation 210152: Buellia aethalea (Ach.) Th. Fr.
When: 2015-07-12
Who: zaca
No herbarium specimen

Notes: Growing on siliceous rock.

Images

538778
538779
539122
Microscopy: Section;
539123
Microscopy: Hymenium;
539124
Microscopy: Asci and spores.

Proposed Names

29% (1)
Recognized by sight
58% (1)
Eye3 Eyes3
Used references: British Flora
Based on microscopic features
Based on chemical features

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Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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Microscopy added.
By: zaca
2015-07-16 19:45:59 CEST (+0200)

Following the key for Buellia and Amandinea in the British Flora I end up with a pair of species, B. leptocline and B. spuria, any of which have smaller spores than my specimen. On the other hand, the species B. aethalea, which according to the description grows on siliceous rocks, plebbles and stoneworks, being often a pioneer species, and having in some cases innate apothecia, is not reachable in that key for specimens with superficial apothecia at maturity; It is only considered following the case of “apothecia remaing immersed, not emergent” (point 13 in the key). In this specimen, most of apothecia are more or less emmersed but others are more like superficial and strongly convex.
I made a test to the medulla and obtained I-; I also tested the thallus (a small fragment joint with an apothecium) and obtained K+ yellow; This reaction I also confirmed under the micro, where no red crystals appeared. However, the description of B. aethalea mention the existence of specimens with such features. On the other hand, a very distinguish property of this specimen is that the epythecium is dark green whereas the hypothecium is dark brown, which agree with the features of B. aethalea. Also the spores agree with the dimensions given for that species (12-18 × 6-10 µm), for which I obtained:
(11.6) 13.4 – 19 (19.4) x (6.1) 6.4 – 9.1 (9.6) µm
Q = (1.8) 1.84 – 2.5 (2.7) ; N = 33
Me = 16.3 × 7.7 µm ; Qe = 2.1
Finally I was note able to find any other species with dark green epithecium and similar dimension for the spores.
Therefore, I propose the name of B. aethalea for this specimen.

Created: 2015-07-15 20:23:29 CEST (+0200)
Last modified: 2015-07-16 19:48:17 CEST (+0200)
Viewed: 15 times, last viewed: 2016-09-14 18:42:04 CEST (+0200)
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