Observation 49840: Physconia muscigena (Ach.) Poelt

When: 2010-07-21

Collection location: Parker Ridge, Banff National Park, Alberta, Canada [Click for map]

Who: Chris Parrish (kitparrish)

No specimen available

Location: 52°10’55.53"N, 117° 6’15.29"W, el. 2265m

Habitat: Growing on soil right at tree-line just below the alpine zone.

Identification: I take this to be a Physconia without soredia or isidia and growing on soil. By the key in McCune and Geiser, that should make it Physconia muscigena. But what about those distinctive white margins to so many lobes? … soredia? … and P. muscigena is meant to have squarrose rhizines. There are plenty of rhizines poking out in these photos, but I don’t see any that are squarrose. Hmmm.

Sharnoff’s Physconia muscigena gallery

[admin – Sat Aug 14 02:04:27 +0000 2010]: Changed location name from ‘Parker Ridge, Banff NP, Alberta, Canada’ to ‘Parker Ridge, Banff National Park, Alberta, Canada’

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Used references: McCune and Geiser, 2009, pp.274-277

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I agree
By: Jason Hollinger (jason)
2010-08-07 21:06:11 CDT (-0400)

I’ve been calling these things P. muscigena, too. There are a few things unusual about this Physconia that together clinch it for me: the lobes are relatively broad, concave, loose, tangled and almost erect in the center; there are never any soredia or isidia (apothecia are relatively uncommon, but when they appear, they have lots of large lobules around the margins); it grows on moss and dead plant material in the alpine. No other species combines these features.

I usually see strongly squarrose rhizines, but strictly speaking, you need to check mature rhizines back from the edges — the ones poking out and visible from above will not always be squarrose or branched. I see the same white edge on the Sharnoff photo in Brodo, but I can’t say I’d noticed it before. Something I’ll have to look for. Maybe it’s because the lobes are concave, so the edges are turned up enough to make them visible?

(Nice specimen, by the way. The ones I’ve seen are always gnarled, sunburnt, nasty things! :)

Created: 2010-08-07 20:08:19 CDT (-0400)
Last modified: 2010-08-13 23:25:19 CDT (-0400)
Viewed: 89 times, last viewed: 2018-11-12 17:33:14 CST (-0500)
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