Part 1 covered the hike, but we didn’t touch at all upon the lichens on Mt. Whitney! So let’s do that here.

Firstly, you might be wondering – what’s the history of lichen collections of Mt. Whitney? Two words: its limited.

Here’s the stats:

Date                      Collector(s)                                   taxa  specimens
15 Aug 1904          J.D. Culbertson & C.F. Baker          5     8
1959?                     R.H. Torrey                                       1     1
11 July 1955           H.A. Imshaug                                  13    43
30 April 1986       S. Souney                                          3     3
2006?                   M. Westberg                                      1     5

Source: CNALH 2016

Mt Whitney, photo by Jason Hollinger
Mt Whitney, photo by Jason Hollinger

For those of you new to this project, the idea is to resurvey the sites that lichenologist Henry Imshaug surveyed in the 1950’s, see if the flora has changed, and if so, pick out some candidate species for further research into climate change biomonitoring using lichens.

You’ll notice that although Imshaug collected 43 specimens, there’s only 13 reported taxa (e.g. species). Some of those specimens are duplicates, but others remain unidentified. And that’s not for lack of effort on Imshaug’s part: the taxonomy of many crustose lichen groups were not yet worked out back in 1955. Rest assured, there’s still problem groups today, but for the most part we’ve got a leg up that Imshaug didn’t have back then.

So, you might be wondering, did we find everything that Imshaug found? From what we currently know of Imshaug’s identified collections, we’re only missing one species: Megaspora verrucosa. And we found a number of macrospecies that Imshaug did not report (Imshaug 1957). These species include Physcia dubia, Rhizoplaca melanopthalma, and Xanthomendoza galericulata. Could these species be extending their range upslope, increasing in elevation, or were these species present back in 1955, but Imshaug simply didn’t collect them?

Some of the species Imshaug did not find in 1955, as well as many that he did find.
Some of the species Imshaug did not find in 1955, as well as many that he did find.

It’s important to note that Imshaug conducted his survey on Mt. Whitney as part of a day hike, and continued on to Kearsarge Pass the next day, followed the next day by Bishop Pass. He was moving and working fast, and working alone as far as we know – so perhaps he overlooked these species. Or perhaps these species are truly expanding their range.

One way to discern whether the establishment of species such as Rhizoplaca melanopthalma is new on Mt. Whitney and other similarly high peaks in the southern High Sierras would be to conduct a few transects from low alpine elevation to high alpine elevation, and simply measure the largest average thalli at each interval. If the size of the average largest thalli decreases with increasing elevation, an inverse relationship, that would be a strong indication that the species is newly establishing at higher elevations. It’s a non-invasive method, would requires minor training, and could be a fun citizen science project. Anyone out there interested?

And now for the lichen photos…

Pleopsidium chlorophanum, otherwise not known in the lower 48 apart from one specimen.
Pleopsidium chlorophanum, assumed to be in the American alpine, but otherwise not known in the lower 48 apart from one specimen (Knudsen 2007).
Carbonea vitellinaria
Carbonea vitellinarian growing as a parasite on Candelariella rosulans.
Lecanora garovaglii
Lecanora garovaglii – note the absence of apothecia: we were unable to find *any* fertile Lecanora species on the summit. Unusual.
Umbilicaria polaris, formerly known as U. krascheninnikovii, a classic alpine species, appearing a little disheveled up on Whitney. Note the whitish colored ridges / wrinkles, that and a pale underside are the distinctive characters.
The greatest diversity of soil crusts was found underneath rock ledges.
The greatest diversity of soil crusts was found underneath rock ledges. These ledges were abundant at the summit, thin, table-top like ledges with ample cave like spaces beneath them.
Caloplaca ammiospila
Caloplaca ammiospila. This was my first encounter with this species, ever. Its striking. Usually genus is orange colored with an orange or gray thallus. The white thallus with brick red discs is distinctive. Imshaug found this species in 1955, finding it again was challenging. It appears to be very rare on Whitney.
Caloplaca jungermanniae
Caloplaca jungermanniae. This is a more typical Caloplaca species than the one above. It belongs to the C. cerina group because of the gray thallus. Note how the thallus hangs onto the outside of orange disc margin, that seemed to stray from the descriptions of that species, but its by far the most common terricolous Caloplaca we’ve found in the alpine on Whitney and the region, owing true to the distribution of C. jungermanniae.


Imshaug, H. A. (1957). Alpine lichens of western United States and adjacent Canada I. The macrolichens. The Bryologist, 60(3), 177-272.

CNALH. (2016). Consortium of North American Lichen Herbaria.

Knudsen, K. (2007). “Pleopsidium” in The Lichen Flora of the Greater Sonoran Region Vol. 3 by Nash

2 Responses

    1. Hi Robin! Yes, isn’t this little P. chlorophanum super duper cute? Like a little button of yellow joy. Its considered extremely rare in North America, but we found a little bit up on Mt. Tiffany in the Northern Cascades, which is alot closer than dear Mt. Whitney… if you find more of it at other peaks as you’reraoming around for Claytonia, take a photo and share the location. As of know there’s only one official report of the species in N. America, and get where its from — Santa Cruz Island. Yup, an alpine species only confirmed report in N. America is from Santa Cruz Island. (see Nash et al2007 Vol 3 — or the Consortium for Lichen Herbaria in North America: CNALH

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