Artemisia tilesii

Perennials, 20-60(-80) cm, mildly aromatic (rhizomes coarse). Stems 1-3, erect, white, tomentose (on distal branches, hairs appressed) or glabrate. Leaves basal and cauline, bicolor (white and green); blades (basal) linear to broadly lanceolate, 3-7(-10) × 2-5(-6) cm, coarsely pinnately lobed (cauline becoming linear distally), faces tomentose (abaxial) or glabrous (adaxial). Heads in compact to broadly branched, paniculiform arrays 1-20 × 2-6 cm. Involucres broadly campanulate, 4-5 × 3.5-4 mm. Phyllaries (violet-brown) oval (outer) to elliptic or lanceolate, sparsely tomentose. Florets: pistillate 9; bisexual 25-60; corollas yellow, 1.5-3 mm, glabrous (style branches included, erect, linear, relatively short, short-ciliate). Cypselae oblong-linear (angular), 1.2-1.5 mm, glabrous. 2n = 18, 36.

Flowering mid summer-early fall. Arctic and alpine tundra, sandy, rocky slopes near shorelines; 0-2000 m; Alta., B.C., Man., N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Idaho, Mont., Oreg., Wash.; Asia (Russia).

Artemisia tilesii has a bewildering array of variation in leaf and inflorescence morphology that has been separated into four infraspecific taxa recognized in some floras. I am unable to separate these taxa consistently and am including them within a broad circumscription of the species.