State Rank Reason (see State Rank above)
Numerous collections at MONTU from Sanders, Lake, Powell, Ravalli, Mineral, Missoula, Beaverhead counties. Grades into P. albertinus.
Stems ascending to erect, 30–80 cm. Herbage glabrous to sparsely puberulent. Basal leaf blades lanceolate to oblanceolate, serrate, 3–9 cm long. Stem leaves lanceolate to ovate, serrate to denticulate, 3–7 cm long, often clasping the stem, larger than the basal blades. Inflorescence with 3 to 8, open verticillasters, glabrous to sparsely glandular. Flowers: calyx 2–5 mm long; sepals lanceolate to ovate, acute, scarious-margined; corolla blue, 12–21 mm long, glandular; anthers glabrous, opening across their full length. Capsule 4–7 mm long (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)