Penstemon sect. Elmigera
Prodr. 10: 329. 1846.
Herbs. Stems glabrous or retrorsely hairy, glaucous or not. Leaves basal and cauline, opposite, leathery or not, glabrous, puberulent, or retrorsely hairy, glaucous or not; basal and proximal cauline petiolate; cauline sessile or short-petiolate, blade subcordate, ovate, spatulate, oblanceolate, lanceolate, elliptic, or linear, margins entire. Thyrses interrupted, ± secund to secund, rarely cylindric, axis glabrous, sometimes retrorsely hairy, cymes 2 per node, sometimes 1 per node (P. labrosus); peduncles and pedicels spreading to ascending or erect. Flowers: calyx lobes: margins entire or erose, broadly scarious, sometimes scarious (P. labrosus), glabrous or glandular-pubescent; corolla red to scarlet or orange, rarely yellow, bilaterally symmetric or nearly radially symmetric (P. eatonii), weakly to strongly bilabiate, not personate, salverform, tubular-funnelform, or tubular, glabrous externally, glabrous or hairy internally abaxially, throat slightly to gradually inflated, not constricted to constricted at orifice, rounded to slightly 2-ridged abaxially; stamens included to exserted, filaments glabrous, pollen-sacs parallel, divergent, or opposite, navicular, dehiscing incompletely, proximal 1/4–1/2 indehiscent, connective not splitting, sides glabrous or hispidulous to lanate-villous; sutures papillate or denticulate, papillae or teeth to 0.1 mm; staminode included or slightly exserted, flattened distally, 0.3–0.9 mm diam., tip straight, rarely recurved, glabrous or distal 5–20% hairy, hairs to 1.5 mm; style glabrous. Capsules glabrous. Seeds brown to dark-brown, angled, 1.4–4.2 mm.
w United States, Mexico
Species 8 (4 in the flora).
Members of sect. Elmigera all exhibit the syndrome of characteristics usually associated with hummingbird pollination. Section Elmigera is not monophyletic; species in the flora area probably are related to species in sect. Glabri (C. A. Wessinger et al. 2016). Four species usually included in sect. Elmigera, but not in the flora area, are Penstemon henricksonii Straw, P. imberbis (Kunth) Trautvetter, P. luteus G. L. Nesom, and P. wislizeni (A. Gray) Straw; all occur in Mexico.
|1||Corollas densely yellow-villous internally abaxially, throats constricted at orifices.||Penstemon cardinalis|
|1||Corollas glabrous or sparsely white- or yellow-lanate internally abaxially, throats not constricted at orifices.||> 2|
|2||Corollas nearly radially symmetric, weakly bilabiate, abaxial lobes projecting to barely spreading.||Penstemon eatonii|
|2||Corollas bilaterally symmetric, strongly bilabiate, abaxial lobes spreading to reflexed.||> 3|
|3||Corollas tubular-funnelform; basal and proximal cauline leaf blades (6–)12–30(–35) mm wide, glabrous or sparsely to densely puberulent.||Penstemon barbatus|
|3||Corollas salverform; basal and proximal cauline leaf blades 3–11 mm wide, glabrous.||Penstemon labrosus|
"/4+timescorollathroat" is not declared as a valid unit of measurement for this property.