Penstemon sect. Ambigui
glabrous, glabrate, or scabrous proximally, not glaucous.
cauline, opposite, not leathery, glabrous or scabrous, not glaucous;
cauline sessile, blade linear, margins entire.
interrupted, cylindric to conic, axis glabrous or scabrous, cymes 2 per node;
peduncles and pedicels spreading or ascending.
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.
glabrous.
dark brown to reddish brown, angled, 1–2.8 mm.
Penstemon sect. Ambigui
Species 2 (2 in the flora).
Section Ambigui includes two subshrubby species of the southwestern and south-central United States and northern Mexico.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Corollas salverform, (14–)16–22(–28) mm. | P. ambiguus |
1. Corollas funnelform, 8–14 mm. | P. thurberi |
