[Beardtongues and Penstemons: The Genus Penstemon East of the Cascade Mountains of Oregon and Washington]

Cascade Penstemon, Cascade Beardtongue, Serrulate Penstemon, Coast Penstemon

Penstemon serrulatus

Cascade penstemon as seen growing in a jersey barrier or retaining wall along forest road #23 at the Mt. Adams viewpoint at the southwestern corner of the mountain, Gifford Pinchot National Forest...........July 10, 2005.

Characteristics:

Cascade penstemon is an upright species of penstemon, with one to several slender stems rising from a woody base to 20 cm - 70 cm in height.

As with most penstemons, the leaves are opposite on the stems. The leaves of Cascade penstemon are all found on the stems. They have short petioles at the bottom, while those above may be sessile or clasping. The lower leaves may be as long as 90 mm. The leaves may be almost entire to very serrate, lanceolate to elliptic or heart-shaped.

Cascade penstemon typically has a single, tight cluster of flowers at the tip of the flowering stem. However, there may be as many as five well-spaced verticillasters present. The sepals are narrow to ovate, with the margins very finely haired. The corolla is a short tube at the base of the flower which expands greatly to a longer, wider tube. The flowers are strongly two-lipped, to 25 mm long. The flower color is purple to blue.

Habitat:

Cascade Penstemon inhabits moist woods and openings from sea level to about 6000 feet. Its habitat is one that is generally moister than that of most other penstemons.

Range:

Cascade Penstemon is found in the west of the Cascade Mountain crest from southern Alaska through British Columbia and Washington to northwest Oregon. It is also found in the Blue Mts. of southeastern Washington.

The photo above shows a close-up view of the inflorescence of cascade penstemon as seen along forest road #23 at the Mt. Adams viewpoint at the southwestern corner of the mountain, Gifford Pinchot National Forest...........July 10, 2005. The flowers are usually found in a single head at the tip of the stem. The anther sacs are horseshoe-shaped and only open at the top. The staminode is flattened and expanded at the tip and typically bears yellow hairs along as much as one-half its length. Those are not seen in this picture.

The photo above shows the sessile, somewhat clasping blades of the upper stem leaves of Cascade penstemon.

The photo above shows the lower leaves of cascade penstemon as seen on loose soils and gravel on slopes above Rd #23 at the Mt. Adams viewpoint at the southwestern corner of Mt. Adams...........June 22, 2005. Note the glaucous willow-herb growing next to it at lower right.

Paul Slichter