- -Ash penstemon blooming amongst rock outcrops (a volcanic dike) at about 7800' in a pass between Light and Drakes Peaks, Fremont-Winema National Forest......June 29, 2019.
The photo at right shows ash penstemon from Newberry Crater, central Oregon.........July 14, 1974. Note that the edges of the leaves are rolled upwards to make the leaf U-shaped in cross-section.
Ash penstemon is a petite penstemon bearing numerous minute flowers. It is a plant which can easily be confused with Penstemon procerus which is found within its range. It is a thin, upright penstemon with one to several stems. It may grow to a height of 40 cm. The leaves are found only on the stems, with no basal tuft of leaves as in Penstemon procerus. They are linear with entire margins and are typically glabrous, occasionally lightly haired. The leaves frequently arch and may be channeled or U-shaped in cross-section. The leaves may attain lengths from 2.5 to 6 cm.
The inflorescence is very narrow, consisting of 3 to 7 many-flowered clusters which may be crowded above to well-spaced below. The upper verticillaster is usually few-flowered with most of the flowers inclined upward or horizontal. The corollas are dark blue to purple in color. The tube is up to 10 mm long and not much expanded. The corolla is strongly two-lipped with the lower lip nearly on the same axis as the tube. The sepals are broad at the base with the tip abruptly squared off, with a short, sharp tip 1.5-2.5 mm long. The anthers are glabrous with rounded sacs. The staminode is expanded slightly at the tip and does not extend beyond the tube. It is covered at the tip with number of short yellow hairs.
Small-flowered Penstemon: Penstemon procerus - This species has an inflorescence which is more densely flowered than Ash Penstemon, especially in the uppermost verticillaster. The lower flowers of each thyrse tend to angle downward. Basal leaves are present with straight, lanceolate to ovate leaves.
Ash penstemon as its name implies is found in dry sandy to rocky volcanic soils, both in the open or among open stands of ponderosa pine and sagebrush. I have commonly seen it at the eastern edge of the Three Sisters Wilderness, just east of Broken Top.
Ash penstemon is found east of the Cascades of central Oregon, from northern Deschutes county and western Crook County south to Lake County and into northern California.
Ash penstemon as seen from Newberry Crater, Newberry Crater Volcanic National Monument........July 14, 1994.