Habit: this delicate evergreen perennial has multiple unbranched stems that rise from a slightly woody base. The stems grow upright, up to 28 inches in height and occasionally present fine hairs. Broad, sharply toothed leaves grow oppositely along the stems and are elliptic to lance-shaped. The lower leaves are attached to stems with petioles (short leafstalks), whereas the upper ones are clasping, lacking petioles. Single or sometimes as many as 5 whorled clusters of flowers top the long stalks and each flower is supported by a hairy calyx. The lavender to deep blue corolla is composed of a short, funnel-shaped tube, narrow at the base, and extended into two lobed lips at the mouth. Flowers bloom June to early August.
Ecology: moist ground in forest openings, wooded slopes, mountains and coastal areas, from sea level to 6,000 feet. Its native habitat ranges from southern Alaska to British Columbia and Oregon, and from the coast to the western side of the Cascade Range.
Growing conditions: enjoys sun or partial shade and moist, yet well-drained soils. This plant requires a good amount of watering, and it is ideal for gardens enduring long, damp winters on the west side of the Cascades. The flowers attract butterflies and hummingbirds.
The species name “serrulatus” refer to the sharply serrated leaf margins. Penstemons are also known as beard-tongues because of their 2-lipped flowers and hairy calyx.