About Penstemon gairdneri Hook.
Penstemon gairdneri Hook. is a subshrub, with stems that are somewhat woody, especially toward their base. Flowering stems grow either upright or outward for a short distance before curving upward, emerging from a branched, woody caudex, and reach 6 to 40 centimeters in height. The stems are covered in stiff, backward-facing hairs and are not glaucous (coated in natural protective waxes). This species also often produces short, densely leaved non-flowering stems that form an open basal mat. Penstemon gairdneri is deciduous in winter; this usually includes its basal leaves, leaving stems as an uncovered mound of bare sticks. Its leaves are numerous, and grow both at the base of the plant (basal) and along the stems (cauline), attaching directly either to the plant base or to the stems. Leaves are not leathery, and may grow alternately along stems, or mostly in opposite pairs on opposite sides of stems. Basal leaves, the lowest leaves on the plant, are 1 to 7 centimeters long and only 1 to 4 millimeters wide. Their shape may be spatulate (spoon-shaped), oblanceolate (reversed spear-head shaped), or linear (narrow, grass-like). When leaves are arranged oppositely, stems bear 8 to 12 pairs of leaves; when arranged alternately, stems have 13 to 25 total leaves. Leaves growing higher on the plant are 7 to 35 millimeters long and only 1 to 3 millimeters wide. Leaf edges are smooth, but revolute (rolled downward). The showy flowers are arranged in a loose inflorescence holding 3 to 12 flower groups. Each group has a pair of peduncles, which unusually bear just one flower each, though they are occasionally branched to hold two flowers. The flowers have a tubular throat that flares out into 5 almost flat petal-like segments. The inside of the floral tube is pale blue to white, while the outside may be blue, violet, or lavender. Flowers may be marked with nectar guide lines, or may lack these markings. As a species, the range of Penstemon gairdneri extends from north central Washington state (Okanogan County) southward to Oregon, growing east of the Cascade Range. In Oregon, it grows through much of eastern Oregon from Wasco and Lake counties east to Idaho. In Idaho, it mainly grows in an area from Idaho County south to Canyon County, with one isolated occurrence further east in Butte County. Penstemon gairdneri grows in open, dry habitats at low to moderate elevation in hills and mountains. It occurs up into juniper and ponderosa pine forests, and is also associated with open sagebrush deserts and the Channeled Scablands on the Columbia Plateau. It can be found at elevations of 100 to 1,800 meters (300 to 5,900 ft).
