Collection location: Jonas Rock Slide, Jasper National Park, Alberta, Canada [Click for map]
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)
John does not report Xanthoria sorediata from the Jonas Rock Slide, but it is known from specimens collected by Bruce Ryan at 1980 m on the Consolation Lake Trail, NE of Moraine Lake, Banff National Park, and others collected by George Otto above Millar Lake in Mount Revelstoke National Park, British Colombia (CNALH range map for Xanthoria sorediata).
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.
CNALH Xanthoria sorediata gallery
Sharnoff Xanthoria sorediata gallery
|I’d Call It That||3.0||5.45||1||(jason)|
sum(score * weight) /
(total weight + 1)
These are all definitely of the same thallus.
As for the potential for X. elegans to be sorediate… You run across a few species here and there in the literature with sorediate “forms”, but I’ve never seen this myself. It must be pretty rare. So, while you can often find sorediate things with apothecia, I think it would be very exceptional to find a fertile species (like X. elegans) with soredia. I’m still skeptical about the whole thing! :)
that there is internal evidence in the four photos to show that they all match perfectly! … so these photos actually did come from the same thallus.
Lichens like these were quite common along a conveniently located old abandoned track through the rockslide. I looked at several of them. I never imagined seeing Xanthoria elegans with soredia, but on the other hand, Elizabeth John does not even mention Xanthoria sorediata from the Jonas Rock Slide. Curious.
The narrow-lobed thing always looks more like X. elegans to me, but sure enough, there it is with soredia. It’s remarkable to see that form mixed with the more typical broad-lobed form on the same thallus. It must be straddling the drip-zone or something, what do you think??