Observation 105881: Melanohalea exasperatula (Nyl.) O. Blanco et al.
When: 2012-06-27
(47.4288° -117.5936° 701m)
Herbarium specimen reported

Notes: Corticolous. Lobes loosely attached. Lower cortex has simple rhizines, short and stumpy, black with white tips, not tapering. Specimens are from canopy having fallen to ground.

Isidia: some branching, bulbous to cylindrical to clavate. One specimen from site is lacking tips on almost all isidia. But isidia do not appear to be hollow as both McCune and Goward state is a distinguishing feature of M. exasperatura.

Upper cortex not pruinose as in M. elegantula. Some samples from site have a lack of cortex and large areas of exposed white medulla that is lacking photobiont, (this is not white pruinia as it seemed in the field with a loupe)

Papillae do not appear to have pseudocyphellae, this would distinguish it from M. elegantula.

No soredia. Apothecia present, cream colored discs.


In the field, this one seemed pruinose, but in the lab showed that there is a cortex lacking in between the isidia, and the medulla underneath has had its photobiont stolen!!! Or it escaped… Otherwise, this specimen looks the same as the others. :)

Proposed Names

45% (2)
Used references: Blanco et al. 2004. “Melanelixia and Melanohalea, two new genera segregated from Melanelia (Parmeliaceae) based on molecular and morphological data” Mycological Research.
Goward el al. “Macrolichens of British Columbia”
McCune et al. “Macrolichens of the PNW
Based on chemical features: C-
61% (2)
Eye3 Eyes3
Recognized by sight: non-flattened, upright, club-shaped isidia, no pruina

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
I think you’re right
By: Jason Hollinger (jason)
2012-08-18 17:40:58 CDT (-0500)

With a super-sharp razor blade you can slice one of these things open, and the medulla is so fluffy that it looks hollow. But I’ve heard people say the smoosh-test works, too.

I think I understand now… :)
By: nastassja (Nastassja Noell)
2012-08-18 16:16:59 CDT (-0500)

what is meant by the isidia being hollow… its not that they are actually hollow like the Hypogymnias, where you can see the inside of the upper and lower cortex when you do a cross section, rather they are hollow in the sense that there is fluffy medulla inside the isidia and when you squeeze them with tweezers the isidia smoosh super easily because of all the air pockets in that fluffy medulla, and in that way are hollow…

Exasperatula indeed! :)

Tricky group
By: Jason Hollinger (jason)
2012-08-18 15:53:08 CDT (-0500)

Although it sounds like it should be easy:

M. elegantula – isidia hemispherical papillae becoming cylindrical to coralloid but not constricted at base (often pruinose)
M. subelegantula – isidia shiny but not “greasy”, upright and decumbent, flattened at least in part, not hollow (often pruinose)
M. exasperatula – isidia shiny and “greasy”, mostly upright, club-shaped and hollow (rarely pruinose)

(taken from one of Trevor Goward’s working keys)

Created: 2012-08-18 15:16:28 CDT (-0500)
Last modified: 2012-08-18 16:17:31 CDT (-0500)
Viewed: 33 times, last viewed: 2016-10-25 11:30:32 CDT (-0500)
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