Observation 86373: Melanelia sorediata (Ach.) Goward & Ahti

When: 2011-07-26

Collection location: Jonas Rock Slide, Jasper National Park, Alberta, Canada [Click for map]

52.0° 117.0°

Who: Chris Parrish (kitparrish)

No specimen available

Location: Jonas Rock Slide, Jasper National Park, Alberta, Canada; 52°25’54.38"N, 117°24’27.02"W, el. 1612 m

Substrate and habitat: growing on boulders in an enormous quartzite sandstone rockslide in the Sunwapta River Valley, 75 km south of Jasper. The elevation of the rockslide extends from 1500 m at the river to 2200 m on the upper slopes (John, 1989, p. 105)

Elizabeth A. John, The Saxicolous Lichen Flora of Jonas Rockslide, Jasper National Park, Alberta, The Bryologist, Vol. 92, No. 1 (Spring, 1989), pp. 105-111.

Elizabeth John (1989, p.108) reports four species of Melanelia from the Jonas Rock Slide:


Melanelia panniformis
“isidia soon growing into small overlapping lobules that +/- cover the thallus” (McCune and Geiser, 2009, p.196);
relative frequency at Jonas Rockslide : 0.35 % cover on sampled rock faces, occurring on steep rock surfaces (Jones, 1998, p.108)


Melanelia disjuncta (Syn.: Melanelia granulosa)
“can easily be distinguished by the lack of pseudocyphellae, and presence of discrete soralia, primarily on the ends of short, erect, lateral lobes” (CNALH);
relative frequency at Jonas Rockslide : 2.12 % cover on sampled rock faces (Jones, 1998, p.108)

Melanelia sorediata
relative frequency at Jonas Rockslide : 3.48 % cover on sampled rock faces (Jones, 1998, p.108)

neither isidiate nor sorediate

Melanelia stygia
relative frequency at Jonas Rockslide : 3.0 % cover on sampled rock faces (Jones, 1998, p.108)

The lichen in this observation shows abundant lobules, but they are not so extensive as to “more or less cover the thallus,” as one would expect in Melanelia panniformis. On the other hand, this lichen does not show the small but distinct pseudocyphellae which are so clearly evident in Jason Hollinger’s photo of Melanelia stygia on CNALH.

CNALH Melanelia disjuncta gallery
CNALH Melanelia sorediata gallery
CNALH Melanelia panniformis gallery
CNALH Melanelia stygia gallery

Species Lists



Proposed Names

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Recognized by sight
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Add Comment
By: Jason Hollinger (jason)
2012-01-15 11:50:28 PST (-0800)

I can find no pseudocyphellae in your excellent photos, so I think it is safe to rule out M. tominii (as you have already done). I’m not good at distinguishing the other two saxicolous sorediate species, though. I lean toward M. sorediata: the soralia are fairly fine, and well-delimited into nice hemispherical mounds. M. disjuncta, so far as I can tell, tends to have coarser more irregular soralia, and according to the literature, the soredia occur on the elevated tips of tiny side-lobes (if you say so! :)

Created: 2012-01-15 10:52:31 PST (-0800)
Last modified: 2012-01-15 12:13:12 PST (-0800)
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