Observation 105898: Melanohalea O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch
When: 2012-06-27
(47.4288° -117.5936° 701m)
Herbarium specimen reported

Notes: This one is not like the other Melanohalea’s I’ve found… no keys are working.

Substrate bark on a ponderosa pine twig, fallen to ground, assuming from canopy or upper area of tree (~70+years old), found alongside Melanohalea exasperata.

Habitat Scattered P. ponderosa grove alongside large and deep wetland trough, sedges/rushes; surrounded by short grass prairie of the mima mounds and basalt outcrops. Presumably a more humid spot than others in the area. Channeled Scablands.

Thallus small, 1.5cm across.

Soredia marginal labriform, some laminal, looks alot like the soredia/soralia on Platismatia wheeleri (similar environmental conditions → similar soredia type?).

Isidia There are no elongated isidia as in M. elegantula and M. exasperata. At best, the isidia is more like isidiated soredia.

Rhizines are furcate, long (average 1mm), slender, tapering, elegant, cream colored (not short and stubby as in M. exasperata_).

Lobes are not elongated and the broad parts of lobe tips range from 3-8mm. At the base lobes are loosely attached by the long rhizines, the other lobes are tufted upwards, reminiscent of a miniature Tuckermanopsis.

Upper cortex green, smooth, not pruinose, thick layer of isodiametric cells (Paraplectenchyma) underneath thin pigmented layer.

Lower cortex cream colored, smooth, thick layer of paraplectenchyma, with rhizines.

Chemistry cortex and medulla: K-. C-. KC-, UV+whitish.

Other no apothecia, no pycnidia seen.

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Eye3 = Observer’s choice
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:) that sounds like fun…
By: nastassja (Nastassja Noell)
2012-08-19 17:20:09 CDT (-0400)

statistically significant, hmmm…

Holy moly!
By: Jason Hollinger (jason)
2012-08-19 17:00:32 CDT (-0400)

If you’re willing to take such drastic steps to identify this little thing, I can’t wait to see what you’ll do when you attack something like Usnea or Hypogymnia!! :)

Ah, here it is: what you clearly need to do is grab a statistically significant set of specimens of T. chlorophylla from this area with as great a variation in morphology as possible, then calculate stats for the variation within each of these characters, like cortex thickness. Then you can place a rigorous confidence value on our hypothetical identification. :)

Tuckermannopsis… :)
By: nastassja (Nastassja Noell)
2012-08-19 16:54:44 CDT (-0400)

It sure seems to fit that genus, maybe it is a really damaged T. chlorophylla… could be: the inflow to that deep trough wetland is from a dairy farm if I’m remembering correctly, whereas the T. chlorophylla from other sites were downwind of a cleaner inflow… here’s what I’m seeing as differences:

……………………………………………… interloper………. ………T. chlorophylla
upper cortex color green brown
lower cortex color white-cream brown-tan
lobe width 3-8mm 2-7mm
entire lobe length up to 10mm 10-27mm
thallus size 1.7cm, crowded lobes 2-4cm, well spaced lobes
rhizines cream, abundant, furcate cream, sparse, simple
thallus thickness 250-400µm 150-400µm
upper cortex thickness 5-12µm 6-12µm
lower cortex thickness 10-130µm 7-22µm
soralia 1-2+mm thick, commonly 2mm,
marginal soralia seems to form from
upper cortex and margins curl downwards
(opposite of labriform)
0.4-1mm thick, usually thiinner
marginal soralia seem to form from both
upper and lower cortices and often curl
upwards, many seem labriform
paraplectenchymatous cortices yes, cortices seem to be purely arenplectenchymatous, no hyphae intermixing, in some cases for 130mm in cross section yes, but only thin layer (2-10µm) on both outer cortices sections is pure parenplectenchymatous tissue, the rest of cortices has hyphae intermixing
Well, now, maybe we shouldn’t rule out Tuckermannopsis chlorophylla after all…
By: Jason Hollinger (jason)
2012-08-19 02:26:43 CDT (-0400)

Yeah, those UV+ white substances are hard to read. Furcate rhizines does tend to point away from Melanelia. It does have paraplectenchymatous cortices. I can’t find record of the type of lower cortex of Melanohalea, but I assume it is paraplect., too. Yeah, Physconia is right out. Rhizines look way wrong for Phaeophyscia.

:) thank you for a little help…
By: nastassja (Nastassja Noell)
2012-08-19 00:13:49 CDT (-0400)

Yup, Corticolous: ponderosa pine, assuming it came from the canopy, was windfallen. Alongside deep trough wetland, mima mounds nearby, tall marsh grasses, presumably a more humid area.

Not pruinose. Lobes are broad (not elongated); do not have papillae, quite erect with rhizines common to be 1mm long — lower lobes are not nearly as attached to bark as M. exasperata.

Broad parts of lobe tips range from 4mm-8mm. The lobes are like you suggest: shaped and sorediated like a miniature Tuckermannopsis chlorophylla based on shape of lobes, but it is so small (thallus 1.5 cm) while at the same time so well developed… and the lobes are seemingly too broad and not elongated enough for Phaephyscia… however the lower cortex seems to be made of isodiametric cells as is the case in Phaephyscia (see attached photo).

And the lower cortex is pale cream, with elongated, tapering, and branching (not perpendicular branching though – more like the branching of plant roots) pale cream elegant rhizines, so that seems to rule out Physconia which in this region would have a dark lower cortex and black squarrose rhizines.

K-, KC-, C- (I’ve even tested K and C on Umbilicaria and Xanthoria just to be sure)… so probably not M. albertana since Lichens of British Columbia lists that as medulla: C+reddish KC+red.

medulla UV+whitish-violetish (I’m not so good with the UV lamp yet, but the medulla does seem positive whitish)

… I’m scheduled to go out this week and find more of this one, I only have this tiny little bit that accidentally got scooped up with the M. exasperata, maybe having more of it will help :)

Little help…
By: Jason Hollinger (jason)
2012-08-18 19:00:36 CDT (-0400)

Could this be a stressed M. albertana?? I’ve tried every other genus I could think of, resorting to checklists to make sure I’m not missing anything. I can’t think of anything else this could be. The isidioid-soredia (or soredioid-isidia?) look more typical of Physconia or Phaeophyscia, but you would notice the difference.

Just to be sure we’re on the same page, though: is this on bark? is it pruinose? how broad would you say the lobe tips are? (they aren’t visible in the two photos) Did you do spot tests and get K- C- KC- for both cortex and medulla? UV on medulla?

Tuckermannopsis can have sparse but elegant long rhizines, but the only vaguely sorediate one is T. chlorophylla, which I’d rule out.

Created: 2012-08-18 18:21:31 CDT (-0400)
Last modified: 2012-08-25 01:55:12 CDT (-0400)
Viewed: 89 times, last viewed: 2017-05-25 22:55:23 CDT (-0400)
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