1. Fine-toothed Penstemon is very similar in appearance to Penstemon wilcoxii. However, the former is found in the Cascades, while the latter is found in northeastern Oregon and into central Idaho.
2. It is an upright species of penstemon, with one to several slender stems rising from 30 cm to 80 cm.
3. The basal leaves are up to 20 mm long, entire to irregularly serrate, with a glabrous to finely hairy or glandular surface. The stem leaves are much larger, opposite, and lanceolate in shape. The stem leaves may be clasping at the inflorescence, or sessile (without petiole) lower on the stem. The stem leaves are also finely toothed.
4. This wildflower has three to ten widely separated verticilasters (clusters) of flowers, with two to four flowers per cluster. The corolla is a bright blue. The throat may be paler with a beard of yellowish hairs. The flowers are strongly two-lipped, and the tube expands somewhat towards the mouth.
Fine-toothed penstemon inhabits open woods and clearings.
Fine-toothed penstemon is found in the Cascade Mountains from the Methow Valley south to just the northern fringe of the Oregon Cascades.