Symphyotrichum welshii (Cronq.) G. L. Nesom

Perennials, 30–100 cm colonial; rhizomes shallow and long, often relatively thick (those of the season each producing a distal rosette near the parent plant). Stems 1–2, ascending to erect (sometimes lax, sometimes reddish), glabrous or sparsely strigoso-villosulous distally (arrays). Leaves (adaxially green, abaxially pale green, sometimes glaucous) thin (proximal) to stiff (distal), margins serrulate (proximal) or entire or nearly so, ± revolute, scabrous, apices mucronulate or sometimes callous-pointed, faces glabrous; basal withering by flowering, petiolate (petioles narrowly winged, sheathing), blades oblanceolate to spatulate, 10–40+ × 4–9+ mm, bases attenuate, margins entire, apices obtuse; proximal cauline withering by flowering, sessile or winged-petiolate, blades lanceolate to oblanceolate, 50–150 × 8–11 mm, bases slightly clasping, margins sparsely serrulate, apices acute; distal sessile, blades linear to linear-lanceolate, 50–130 × 4–6 mm, gradually reduced distally, bases ± clasping, apices acute. Heads in open, slender, leafy, paniculiform or racemiform arrays, branches ascending. Peduncles 0.5–2 cm, scabro-villosulous, bracts linear, scabro-ciliolate. Involucres cylindro-campanulate, 4–7 mm. Phyllaries in 3–4 series, lanceolate (outer) to linear (inner), ± unequal, bases indurate, margins hyaline, erose, distally scabro-ciliolate to ciliolate, green zones ± foliaceous (outer) or lanceolate, apices acute to acuminate, sometimes purplish, faces glabrous. Ray florets 18–25; corollas pink to white, laminae 9–12 × 0.8–1.5 mm. Disc florets 23–60; corollas pale yellow, 3.8–6.4 mm, tubes shorter than funnelform throats, lobes narrowly triangular, 0.4–0.8 mm. Cypselae pinkish tan (nerves stramineous), obovoid, ± compressed, 0.8–1.6 mm, 3–5-nerved, faces sparsely strigillose; pappi white, 2.8–5.3 mm. 2n = 16.

Aster welshii Cronquist in A. Cronquist et al., Intermount. Fl. 5: 291, fig. p. 293. 1994

Symphyotrichum welshii (formerly Aster welshii) is an imperiled species of flowering plant of the aster family (Asteraceae) endemic to only certain western states in the United States, specifically Arizona, Idaho, Montana, Utah, and Wyoming, and is found at elevations of 1,300–2,300 meters (4,300–7,500 feet). It is perennial and herbaceous and may reach a height of 1 meter (3 feet 3 inches). Its bloom time is August–October, and it grows in wet soils that occur in dry areas.

Symphyotrichum welshii is classified in the subgenus Symphyotrichum, section Symphyotrichum, subsection Dumosi. It is one of the "bushy asters and relatives."

Symphyotrichum welshii là một loài thực vật có hoa trong họ Cúc. Loài này được (Cronquist) G.L.Nesom miêu tả khoa học đầu tiên.