Artemisia capitata (Nutt.) Sòn. Garcia, Garnatje, Mc Arthur, Pellicer, S. C. Sand. & Vallès-Xirau

Sphaeromeria capitata Nutt. Trans. Am. Phil. Soc. II. 7: 402
1841.
Tanacelum capitatum T. & G. FI. N. Am. 2: 415. 1843.
A cespitose tufted perennial, suffruticose at the base; stems about 1 dm. high, finely canescent; leaves mostly crowded at the base, 1-3 cm. long, silvery-canescent, ternately or bitemately diided into linear or linear-oblanceolate divisions; heads few, capitately clustered at the end of the stems or sometimes 1 or 2 in the upper axils below the terminal cluster; involucre broadly campanulate, 4-5 mm. high and about as broad; bracts 6-8, obovate, lightyellow, erose, silky; ray-flowers 5-6; corollas 2 mm. long, ovoid, 3-4-lobed; disk-flowers 12—15; corollas campanulate, with a short tube, 2.5 mm. long, glandular-puberulent; achenes 2 mm. long, subcylindric, tapering at the base, 5-ribbed, truncate at the summit, glabrous.
Type locality: Red Buttes on the Platte, Wyoming. Distribution: Wyoming and southern Montana.