E. robustum is a rare western Nevada native it is found growing on eroding exposed slopes, composed of course unstable altered andesite. In the wild this species habitat is limited to these sights.
Blooms mid-late June. The flowers are creamy yellow, infloresence is umbellate held 3”-4”
above the foliage. The plants grow as tufted mounding mats 8”-10” tall and up to 8” across. The flowering stems are stout and grow erect. The leaves are grouped into rosettes. They are large ovate shaped. Densely white tomentos above and less so on the lower surface.
At one time this was listed as a variety of E. lobbii. It's designation is currently that of a separate species.
E. robustum dose not require an andesite growing medium. I grow it on a 50-50 mix of
mineral clay and disintegrated granite. Does well in a garden setting.
These photos are of E. robustum growing in my garden.