Comprehensive DescriptionRead full entry
General: Figwort Family (Scrophulariaceae).
Royal penstemon is a perennial herb/forb reaching 3 to 6 dm (1 to 2 ft) tall. Several ascending to erect stems arise from a branched caudex. Flowers are sky blue reaching 4 cm (1.5 in) long and about 1 cm (0.4 in) wide at the mouth. Leaves are entire and narrow, to 15 cm (6 in) long and 1 to 12 mm (0.04 to 0.5 in) wide, rounded to acute at the tip. The leaves are mostly sessile with some of the upper leaves clasping the stem. Anthers are blue-margined, glabrous, with sacs about 2mm (0.08 in) long, partially dehiscent; the suture line not reaching the connective (Welsh 2003). Flowering season is from May to July. There are approximately 400,000 seeds/lb (USDA-NRCS 2008).
Close-up of flowers.
Derek Tilley, USDA NRCS Idaho PMC
Distribution: Royal penstemon is found in scattered populations throughout the Great Basin Floristic Province. The species is common in western Utah, southern Idaho, and most of Nevada and into east Cascade and Sierra portions of Washington, Oregon and California.
Habitat: Royal penstemon inhabits dry flats, slopes and draws in the sagebrush-grass, mountain shrub and juniper forestland communities. Plants typically occur at low to middle elevations in lowlands and foothills from 0 to over 10,000 feet (Hitchcock et al 1959).