Davidson’s Penstemon

There are over 50 Penstemon species, many of which are very difficult to identify.  (If you type “penstemon” into the CalFlora Website, over 100 different plants appear.) Davidson’s penstemon (Penstemon davidsonii) is a penstemon that, because of its form and habitat, is easier to recognize than many of its “cousins”.

Davidson’s penstemon grows on open, rocky slopes and ledges in the higher mountains. This member of the Snapdragon Family is considered an alpine plant. It can be found in British Columbia, Washington, Oregon, California and Nevada.

Davidson’s penstemon has many woody, branching stems that root at the nodes. The plant assumes a low, mat-like or cushion-like form. This wildflower is sometimes considered a shrub because it grows from a woody base.

The leaves of this native perennial are opposite, evergreen, leathery and shiny. The small, ovate leaves are often slightly toothed.

The blue to purple-violet terminal flowers have a long, swollen, somewhat flattened corolla tube. The five petals are joined into two lips: the upper lip has two petals(lobes) and the lower lip three. The petal lobes are short, rounded and flaring. Like all penstemons, Davidson’s penstemon has four fertile stamens arranged in pairs and one sterile stamen that rests on the throat. Both the anthers and the projecting lower lip have woolly hairs. There are also five sepals surrounding the corolla tube.

Davidson’s penstemon fruits are many seeded capsules.

Davidson’s penstemon plants demonstrate good adaption to survival at higher latitudes:

*The plant is short thus it avoids the brunt of the wind and with its small profile can utilize rocks, hollows and boulders as windbreaks.

*Because it is evergreen, Davidson’s penstemon can begin to grow and photosynthesize early as soon as the snow melts thus maximizing the short growing season.

*The stems are closely grouped and can act as windbreaks and shelter for each other.

*Davidson’s penstemon flowers are a darker color therefore they absorb sunlight rather than reflect it.

*The leathery leaves help conserve moisture, often lacking in alpine environments.

Other common names for P davidsonii are creeping penstemon and beardtongue (because of the hairy stamens and corolla throat). George Davidson (1825 – 1911), an astronomer and geographer who collected plants in California, is honored by the species designation. There is more than one suggestion for the etymology of the genus Penstemon. However, all the derivations revolve around the five stamens.

These specimens were photographed in late June and early July along Garfield Peak Trail at Crater Lake National Park (Oregon) and at Glass Mountain (Siskiyou County CA) near Lava Beds National Monument.


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2 Responses to Davidson’s Penstemon

  1. tonytomeo says:

    Ha! This one I really do remember! I found it at Castle Crags! I have not seen in in many years though.


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