Subalpine Aster

Eurybia merita occurs mainly from the Interior Mountains and Plateaus system to the Rocky Mountains, and is disjunct to the Black Hills of South Dakota. It reaches California in Siskyou County; the species has been overlooked in this state (e.g., G. A. Allen 1993) because of misidentification with E. radulina. S. L. Welsh et al. (1987) reported E. sibirica from the Uinta Mountains of Utah (Summit County), which A. Cronquist (1994) attributed to var. merita.

Plants (2–)10–50 cm, clonal and clumped, eglandular; rhizomes creeping to ascending, long or short, scaly, woody with age. Stems 1–3+, usually ascending, sometimes decumbent, purplish, occasionally branched basally, sparsely villosulous, densely so distally. Leaves cauline (dark green abaxially, paler bluish green adaxially) firm, ± markedly veined, margins entire or serrulate, scabrous to strigoso-ciliate, teeth mucronate, slightly indurate, apices obtuse to acute, mucronate, abaxial faces glabrescent to sparsely villous along veins, adaxial glabrescent or sparsely (proximal) to ± densely (distal) villoso-strigose or strigose; proximalmost withering by flowering; proximal narrowly winged-petiolate or sessile, petiole bases sheathing, blades spatulate to obovate or oblanceolate, 10–43 × 2–16 mm, smaller than mid, bases attenuate to cuneate, subclasping (if sessile); mid sessile, blades lanceolate or oblong-lanceolate to oblanceolate, narrowly obovate, or spatulate, 20–80 × 4–35 mm, gradually reduced distally, bases rounded or subauriculate to widely attenuate or cuneate; distal (arrays) sessile, lanceolate to lance-ovate or elliptic to oblanceolate, 6–52 × 1–17 mm, rapidly reduced distally, margins often slightly purplish. Heads (1–)5–50, usually in open to compact, corymbiform arrays, rarely borne singly. Peduncles villosulous; bracts 0–3, lanceolate to spatulate, leaflike to distally phyllary-like (bases indurate, margins purplish), mostly foliaceous. Involucres campanulate, 6–9 mm, shorter than pappi. Phyllaries 30–65 in 4–5 series, often purplish, oblong or lance-oblong (outer) to lance-linear or linear (inner), unequal, membranous, bases indurate, rounded, dark green zones diffusely diamond-shaped to lanceolate in distal ¹ / 3 – ² / 3 (outer, seldom foliaceous) to ¹ / 5 or none (inner), margins ± dark purple, narrowly scarious, erose, densely villoso-ciliate, apices appressed or sometimes loose and ± squarrose, acute to obtuse, often apiculate, faces usually villous, rarely glabrous. Ray florets (10–)14–32; corollas purple to violet, 7–12(–15) × 1–1.7 mm. Disc florets 30–60; corollas pale to cream-yellow, lobes pink-tinged, 5–7.6 mm, slightly ampliate, tubes equaling or slightly longer than funnelform throats, lobes erect, triangular, 0.6–1.3 mm. Cypselae brownish, fusiform-obconic, slightly compressed, ca. 3.4 mm, ribs 8–10 (pale, strong), strigillose; pappi of cinnamon to yellowish bristles 5–6 mm, longer than disc corollas. 2n = 36.

Aster meritus A. Nelson, Bot. Gaz. 37: 268. 1904; A. richardsonii Sprengel var. meritus (A. Nelson) Raup; A. sibiricus Linnaeus var. meritus (A. Nelson) Raup

Eurybia merita, commonly known as the subalpine aster or arctic aster (not to be confused with Eurybia sibirica, which shares the latter common name), is an herbaceous perennial native to northwestern North America, primarily from the Interior Mountains and Plateau system and Rocky Mountains in Canada, stretching south to Utah and extreme northern California. It is found largely in drier, open areas, generally at subalpine levels in mountains, though in more northern areas it is more common at lower elevations. It is similar in appearance to Eurybia sibirica, but their ranges only overlap near the border between the US and Canada, where E. sibirica is generally found at higher elevations than its relative. The flowers emerge in the late summer and display purple to violet ray florets and pale or creamy yellow disc florets.