Plant of the Week
Littlecup Penstemon (Penstemon sepalulus)
By Teresa Prendusi
Commonly known as beardtongues, the genus Penstemon (Scrophulariaceae), is the largest plant genus endemic to North America with over 270 species. Most Penstemon species are found in the western U.S. with the Intermountain region representing the center of diversity and evolution. It is one of our showiest native genera - displaying a huge array of shapes, sizes, color forms, and ecological niches. Most species are bee pollinated, although some groups have evolved to pollination by hummingbirds, moths, and butterflies. Because many penstemons are restricted to arid or semi-arid conditions, they are rapidly becoming the darlings of native plant and rock gardeners in the arid states.
Littlecup penstemon is one of Utah’s many rare and endemic Penstemon species. This perennial semi-shrubby species is 17 to 35 inches tall, with many branches arising from a woody base. The narrowly elliptic leaves are opposite, entire, and acute at each end and about 3 to 10 mm wide. Its beautiful tubular lavender-violet flowers are borne in a circular arrangement of whorls along the stems. They are about 20 to 29 mm long with red-violet lines on the throat of the lower lip. The stamens are included in the throat or the longer pair reaching the orifice of the flower. Anthers are horseshoe shaped and dehise across the top of the confluent apex of the anther sac. The sterile stamen (staminode) is white, glabrous, and slightly dilated.
Penstemon sepalus is found in rocky canyons in sagebrush, oak, chokecherry, aspen, and Douglas fir communities at elevations of 1500 to 2500 meters in the southern portion of the Wasatch Range in Utah.