Pygmy Aster

Symphyotrichum pygmaeum has long been included within or associated with Eurybia sibirica. Though similar in appearance, the two species can be distinguished by the glands present on S. pygmaeum on the distal leaves and phyllaries.

Perennials 1.5–15 cm, cespitose; with short, branched caudices, long-rhizomatous (both wiry). Stems 1–10+, decumbent to ascending (purple), sparsely or densely villous to woolly distally. Leaves firm, margins usually entire, sometimes remotely pauci-serrulate, sparsely villoso-ciliate, apices obtuse to acute, sometimes mucronate; basal often withering by flowering, petiolate (petioles widely winged, sheathing), blades spatulate, 5–19 × 2–4 mm, bases attenuate, apices rounded, faces glabrous or sparsely villous proximally; proximal sessile, blades lanceolate to oblong-lanceolate or (sometimes) -spatulate, 30–50 × 3–10 mm, bases ± clasping, apices obtuse to acute, faces glabrous or sparsely villous; distal sessile, blades lanceolate to oblong, 13–19 × 2–4.5 mm, bases clasping to cuneate, apices acute to obtuse, faces sparsely woolly, sometimes sparsely stipitate-glandular. Heads borne singly. Peduncles densely villous to lanate distally, bracts 0. Involucres hemispherico-campanulate, 9–12.5 mm. Phyllaries in 3–4 series (dark purple), lance-oblong or oblong (outer) to linear-lanceolate or sometimes linear (inner), subequal, outer ± herbaceous, bases not indurate, margins herbaceous (outer) to narrowly scarious and erose proximally (inner), strongly purple, villoso-ciliate in green portion, green zones (inner) ¹ / 2 – ² / 3 of distal portions, apices acute to acuminate, inner sometimes apiculate, appressed to loose and squarrose (particularly outer), faces woolly to densely villous, sparsely to moderately stipitate-glandular. Ray florets 16–28; corollas purple to violet, laminae 12–18 × 2–3.2 mm. Disc florets 53–55; corollas yellow, 5.6–6.5 mm, throats funnelform, lobes triangular, 0.5–0.8 mm (red or white clavate-hairy). Cypselae fusiform to cylindro-obconic, ± compressed, [size unknown], 4–7-nerved (faint), faces ± densely strigillose; pappi whitish to yellowish, 5–7.2 mm.

Aster pygmaeus Lindley in W. J. Hooker, Fl. Bor.-Amer. 2: 6. 1834; A. sibiricus Linnaeus subsp. pygmaeus (Lindley) Á. Löve & D. Löve; A. sibiricus var. pygmaeus (Lindley) Cody; Eurybia pygmaea (Lindley) G. L. Nesom

Symphyotrichum pygmaeum (formerly Eurybia pygmaea and Aster pygmaeus) is a species of flowering plant in the family Asteraceae. Commonly known as pygmy aster, it is a perennial, herbaceous plant that may reach heights of 1.5 to 15 centimeters (1⁄2 to 6 inches). Its summer-blooming flowers have purple to violet ray florets and yellow disk florets.

S. pygmaeum is native to north Alaska, Northwest Territories, and Nunavut, and it grows at up to 200 meters (660 feet) or more above sea level in moist sand dunes, sandy or silty stream banks, gravelly tundra, and similar habitats.

As of December 2022, it was classified by NatureServe (as Eurybia pygmaea) as Apparently Secure (G4) globally; Apparently Secure (S4) in Northwest Territories and Nunavut; and, Imperiled (S2) in Alaska. Its global status was last reviewed by NatureServe on 23 June 2016. Several known locations of the plant, especially in Alaska, are near oil field developments, increasing the potential threat to its survival in those areas. "The sand and gravel sites favored by this species are [...] prized for material sites by mineral and oil exploration and development companies."

S. pygmaeum herbarium specimen S. pygmaeum herbarium specimen close-ups