File:Alpine sagebrush, Artemisia rothrockii (White Mountains form) (42915290791).jpg

alpine sagebrush, Artemisia rothrockii (White Mountains form), Nevada, White Mountains, Middle Creek, Fishlake Valley drainage, elevation 3187 m (10455 ft).

This highest-elevation sagebrush of the White Mountains has previously been confused with low sagebrush (Artemisia arbuscula), a species found mainly farther north and east, from which it differs in having larger heads, persistently white-felty stems, and spreading habit with stems often rooting from the lower nodes.

More recently the White Mountains plants have been considered to be a local whitish-hairy form of Artemisia rothrockii, which is otherwise found in the Sierra Nevada and the mountains of southern California, and extends also into the Sweetwater Mountains.

After comparing descriptions and images of "typical" Artemisia rothrockii, however, I am becoming convinced that the White Mountains plants represent an unnamed species, apparently endemic to the range. Besides the lower growth form and dense grayish-white pubescence, it seem to differ from A. rothrockii in having shorter and broader leaves, and flowering stems mostly racemose and unbranched or with few short branches.

Finding the very same plants isolated here in bristlecone-limber pine forest at the Nevada end of the White Mountains, well separated from related species, helps to solidify this opinion.