Engelmann’s aster

Aster elegans (Nuttall) Torrey & A. Gray var. engelmannii D. C. Eaton in S. Watson, Botany (Fortieth Parallel), 144. 1871 (as engelmanni); A. engelmannii (D. C. Eaton) A. Gray

Perennials 50–120(–150) cm (with caudices or stout rhizomes). Stems ascending to erect, glabrate or pilose, eglandular to ± densely glandular. Leaves: mid and distal blades elliptic to lance-ovate, 5–10 cm × 15–35 mm, faces glabrous and eglandular or abaxially villous and/or ± glandular. Heads 5–15(–40) in racemiform to corymbiform arrays. Peduncles often stipitate-glandular. Involucres turbinate, 7–10 mm. Phyllaries in 4–6 series (strongly unequal, often reddish apically), linear to lance-ovate, acute to acuminate, pubescent to glandular or glabrate abaxially, villous adaxially, especially distally (appearing ciliate toward tips). Rays usually 8 or 13, white to pink. Cypselae usually pilose; pappus bristles in 2 series, barbellate. 2n = 18.

Flowering Jul–Aug. Open coniferous forests, montane and subalpine meadows; 500–3000 m; Alta., B.C.; Colo., Idaho, Mont., Nev., Utah, Wash., Wyo.

Forms of Eucephalus engelmannii from the Cascade Mountains with leaves more densely pubescent on the abaxial faces may reflect intergradation with E. ledophyllus.