Wildflowers: Arnica, Denali National Park, Alaska

Is this Nodding Arnica (Arnica lessingii) or Snow Arnica (Arnica frigida)? These plants were found late June in Denali National Park. I suspect they are Nodding Arnica, but I am not sure.

 

I know nothing about this, but am adding links to a page for each of several excellent photos by Paul Slichter, from The Sunflower Family in Denali National Park and Preserve (from Wildflowers of Denali National Park and Preserve).

Lessing's Arnica, Nodding Arnica (Arnica lessingii)
Lessing's Arnica, Nodding Arnica: Arnica lessingii (Synonyms: Arnica angustifolia var. lessingii, Arnica lessingii ssp. norbergii)

Frigid Arnica, Snow Arnica (Arnica frigida, or on this page and Wikipedia as Arnica griscomii ssp. frigida)
Frigid Arnica, Snow Arnica: Arnica griscomii ssp. frigida (Synonyms: Arnica frigida, Arnica louiseana ssp. frigida, Arnica louiseana var. frigida, Arnica louiseana var. mendenhallii, Arnica louiseana var. pilosa)

 

Thank you Wendy! I have seen these pages, but I am still undecided. I was hoping someone knowing these species would chime in.

Paalo

 

I would lean toward it not being Arnica lessingii, though I am not familiar with Arnica frigida.

 

Thanks Daniel! I tend to agree. Having looked at numerous web pages, I now suspect they are Snow Arnica. One uncertainty, of course, is the degree of mislabeling of photos posted on the internet. Thats one of the dangers trying to determine species solely based on online photos.

Paalo

 

Well, my personal experience with Arnica lessingii is that it very much nods and the ray flowers hang instead of flare.

 

Very good! I think we can conclude that Snow Arnica is the most likely species. Based on the species list from Denali National Park, I don't think these plants resemble any of the other Arnica's reported from the area: http://ecologicalatlas.uaf.edu/oq-content/uploads/DenaliFloraAppSpeciesList.pdf

Thank you Wendy and Daniel for your help.

Paalo