Penstemon cardinalis ssp. regalis (Guadalupe Penstemon)
Perennial herb; stems 40-100 cm tall; leaves opposite, thick, to 6 cm long and 5 cm wide, heart-shaped; inflorescence secund (one-sided), the cymules paired, well spaced, 2-flowered; calyx 4-6 mm long; corolla 26-30 mm long, red, narrowed at the mout...