Eriogonum umbellatum is found widely across the western states of AZ, CA, CO, ID, MT, NV, OR, UT, WA, WY, and Canada in BC and AB. With over thirty widely spread varieties, it is also one of the most diverse of the Genus. Found from the high alpine ridges down to the high desert basin environments.
The flowers are held erect in umbellate Inflorescence, ranging in colors form white to yellow to red. (yellows being the most often encountered). The flower stems normally display a whorl of bracts mid way up their length but not in all varieties. The leaves can be any thing from tomentose to glabrous, normally oblong-oval in shape, green to gray green in color adaxially depending on the density of floccose hairs present. Abaxially the surface is normally tomentose, white/gray to gray/green in color.
There are many garden worthy varieties from low mat forming miniatures to sizable spreading shrubs. Some of the more well known are var. porteri, var. polyanthum, var. humistratum, var. aureum, var. proliferum and the selection 'Alturas Red'.
The variety encountered along the Sierra Nevada crest of CA and Siskiyou Mountains of OR eastward through NV, into southwestern, UT and northwestern,AZ is Eriogonum umbellatum var. nevadense. It is found at elevations ranging from 8000'> in the Great Basin Desert region. This grows as a mounding shrub 12-18" tall and 12"-24" across with bright yellow flowers and gray/green foliage.
Around the Reno area we often see var. nevadense expressed in two forms. The lower elevation form slightly taller with greener leaves and a more open airy inflorescence, And a higher elevation form, noticeable shorter, with grayer leaves and denser, lighter colored inflorescence. I had always thought that they were differant varieties however Dr. Reveal identified both forms as var. nevadense. In cultivation both forms keep their natural growth habits. I had the good fortune to test this, for several years, as I planted one of each form right next to each other in the garden.
The first three photos show the lower elevation form . The last three show the high elevation forum.