Penstemon sect. Ambigui
Contr. U.S. Natl. Herb. 20: 326, 333. 1920.
Subshrubs. Stems glabrous, glabrate, or scabrous proximally, not glaucous. Leaves cauline, opposite, not leathery, glabrous or scabrous, not glaucous; cauline sessile, blade linear, margins entire. Thyrses interrupted, cylindric to conic, axis glabrous or scabrous, cymes 2 per node; peduncles and pedicels spreading or ascending. Flowers: calyx lobes: margins entire or erose, broadly scarious, glabrous; corolla pink or lavender to violet, bilaterally symmetric, bilabiate, not personate, salverform or funnelform, glabrous externally, glandular-pubescent internally abaxially, throat slightly inflated, not constricted at orifice, rounded abaxially; stamens included or longer pair reaching orifice or barely exserted, filaments glabrous, pollen sacs divergent, explanate, dehiscing completely, connective splitting, sides glabrous, sutures smooth; staminode included, terete or slightly flattened distally, 0.1 mm diam., tip straight, glabrous; style glabrous. Capsules glabrous. Seeds dark brown to reddish brown, angled, 1–2.8 mm.
w United States, n Mexico.
Species 2 (2 in the flora).
Section Ambigui includes two subshrubby species of the southwestern and south-central United States and northern Mexico.