Artemisia norvegica subsp. saxatilis

Perennials, 25-40(-60) cm (not cespitose), mildly aromatic (roots often horizontal, woody). Stems 1-3, erect to ascending, green or reddish, simple, glabrous or sparsely tomentose. Leaves mostly basal (in rosettes, petiolate), bright green; blades (basal) broadly lanceolate, 5-8(-10) × 2-3(-4) cm, 1-3-pinnately lobed (apical lobes 1-7 × 1.5-3 mm; mid cauline sessile, pinnately lobed; on flowering stems, sessile, linear, entire), faces glabrous or hairy. Heads (nodding, proximalmost on peduncles to 50 mm) in racemiform arrays 10-17 × 1-2 cm. Involucres globose, (4-)5-8 × 4-10 mm. Phyllaries ovate-lanceolate to elliptic (margins dark brown to black), sparsely hairy to villous. Florets: pistillate 6-20; bisexual (30-)50-70; corollas yellow or red-tinged, 1.5-2.5(-3.5) mm, long-hairy. Cypselae ovoid-oblong (angular), ca. 2.5 mm, glabrous or villous. 2n = 18, 36.

Flowering mid-late summer. Coastal, arctic, subalpine to alpine habitats, boreal forests, moist soils; 0-3800 m; Alta., B.C., Yukon; Alaska, Calif., Colo., Mont., Utah, Wash., Wyo.; e Asia (Russian Far East).

Variation within Artemisia norvegica in North America is not well understood and, for that reason, this treatment represents a conservative taxonomy with only one subspecies for the flora area. Subspecies saxatilis differs from typical A. norvegica primarily by its larger heads. European plants have involucres less than 10 mm in diameter. Chromosome number may be used to justify separation of taxa either at the level of subspecies or species. If separated as distinct species, then A. arctica is the name for North American plants. The diploid A. arctica (2n = 18) and tetraploid A. comata (2. = 36) are treated as separate species by R. Elven et al. (pers. comm.).