Sepp talks about this in Rebel Farmer. Anyone know what the species name is for this? And maybe where in the U.S. it can be found?
Google search didn't reveal much.

Is this what your looking for? Salix petrophila

I don't know, but what Sepp describes sounds like a tree/bush/shrub.
That looks like groundcover to me.
Wondering if this is it
Salix hegetschweileri

Here is a list of Alps Salix that I found
http://www.naturetrek.co.uk/reports_new/CHE02_report_080615_Wengen_Alpine_Flowers_of_the_Swiss_Alps.pdf

Salix aurita Eared Sallow
Salix breviserrata Finely-toothed Willow
Salix foetida Above Grutschalp
Salix hastata Large-stipuled Willow Lauberhorn
Salix glaucosericea Silky Willow Lauberhorn
Salix hegetschweileri Alpine Willow
Salix helvetica Swiss Willow Planted. Murren
Salix herbacea Least willow
Salix laggeri Lagger's Willow
Salix myrsinites Whortle-leaved Willow
Salix reticulata Net Leaved Willow
Salix retusa Retuse-leaved Willow
Salix serpyllifolia
Salix viminalis Osier Occasional. Riversides

Most 'alpine' species of willow are low - usually under 6'.

There is one called Salix alpina. I don't know if that is the one he refers to or not.

http://www.growsonyou.com/plant/Salix_alpina