Porter's Aster, Smooth White Aster

Symphyotrichum porteri (A. Gray) G.L. Nesom is the foot hills and near the Rocky Mountain Front Range in southeastern Wyoming, Colorado and northeastern New Mexico (Brouillet et al. 2006; FNA). The species has glabrous leaves without axillary clusters, scabrous margins, and inforescence branches ascending, peduncle bracts 1–3; ray laminae white, 6.8–12 × 0.7–1.8 mm; disc florets (30–)40–75(–103). The species is diploid 2n=16.