Timberline Sagebrush

Artemisia rothrockii is known only from the central and southern Sierra Nevada and the White Mountains of California. In the Rocky Mountains, A. spiciformis has been confused with A. rothrockii. Distinctive chemistry and anatomical structure of the leaves support the distinctness of A. rothrockii (L. M. Shultz 1986b). Intermediate characteristics suggest a hybrid origin from races of A. cana and A. tridentata.

Shrubs, 20–50 cm (sticky-resinous and dark green throughout), pungently aromatic; not root-sprouting (trunks relatively narrow). Stems white (becoming dark gray with age), canescent (bark exfoliating). Leaves persistent, light or dark gray-green; blades long-cuneate to lanceolate, (0.4–)1–1.5(–2) × 0.2–0.4 cm, 3-lobed (lobes to ¹/3 blade lengths, rounded, margins sometimes entire, somewhat wavy), faces densely to sparsely canescent, gland-dotted, sticky-resinous. Heads (erect, sessile or pedunculate) in paniculiform arrays, 5–15 × 1–2(–3) cm. Involucres broadly ovoid, 3–5 × 4–6 mm. Phyllaries (usually gray-green) ovate, densely or sparsely canescent. Florets 12–20; corollas 2.5–3.5 mm. Cypselae 0.8–2 mm, (smooth), resinous. 2n = 36, 54, 72.

Artemisia tridentata Nuttall subsp. rothrockii (A. Gray) H. M. Hall & Clements; Seriphidium rothrockii (A. Gray) W. A. Weber

Artemisia rothrockii A. Gray, Bot. Calif. 1: 618. 1876
Artemisia trifida A. Gray, Bot. Calif. 1: 405, in part. 1876.
A low shrub, 2—4 dm. high; bark Ught-brown; leaves mostly narrowly cuneate and 3-4cleft into oblong lobes, and some of them entire and oblong, 1-2 cm. long, sparinglj* and finely cinereously canescent, often glabrate, more or less %'iscid; heads rather few in an interrupted spike-like inflorescence, 1-3 short-peduncled or subsessile at each intemode; involucre hemispheric-campanulate, about 4 mm. high, 4-5 mm. broad; bracts 10-12, imbricate in 3-4 series, brown, shining, one of the outer bracts often a little foliaceous, abruptly acuminate, the rest ovate, acute, half as long as the innermost; inner bracts elliptic, obtuse, scarious; flowers 10-12; corollas trumpet-shaped, 3 mm. long, 5-toothed, sparingly glandular-granuliferous; style slightly exserted; achenes nearly 2 nun. long.
Type locality: Sierras of Tulare County, California. Distribution: Sierra Nevada, California and Nevada.

Artemisia rothrockii is a North American species of sagebrush known by the common names timberline sagebrush and Rothrock's sagebrush.

Artemisia rothrockii is endemic to California, where it is native to parts of the Sierra Nevada, the White Mountains, and the San Bernardino Mountains. It has been recorded from the Kern Plateau, Mount Dana, Angora Peak, and the vicinity of Fallen Leaf Lake. It grows in the dry transition between mountain meadows and forests. It can also tolerate wet conditions, surviving waterlogging during snowmelt.

Artemisia rothrockii grows at elevations between 2000 and 3500 meters. This mountain shrub grows to heights of 20 to 50 centimeters, producing many upright stems from a narrow trunk. The evergreen foliage is dark green, glandular, sticky, and very aromatic. New twigs and leaves are somewhat woolly, but older parts are hairless. The narrow inflorescence holds clusters of flower heads lined with rough, shiny, slightly hairy phyllaries and containing yellowish disc florets. The fruit is an achene up to 2 millimeters long, sometimes with a pappus.

The species is named for American forester Joseph Trimbel Rothrock, 1839 – 1922.