Aster occidentalis (Nuttall) Torrey & A. Gray var. intermedius A. Gray in A. Gray et al., Syn. Fl. N. Amer. 1(2): 192. 1884; A. vallicola Greene

Plants 40–80 cm. Leaves narrowly elliptic to oblanceolate. Heads 10–50(–75). 2n = 32, 48. 64.

Flowering Jul–Aug. Grasslands and montane meadows, open coniferous forests; 1200–2000 m; B.C.; Calif., Idaho, Nev., Oreg., Wash.

Variety intermedium is found mainly in the northern part of the species range and is only occasional in California and Nevada.