Penstemon speciosus (aka. Royal or Showy Penstemon)

Submitted by Weiser on Tue, 05/25/2010 - 15:04

One of my favorate western Penstemons is Penstemon speciosus. Found from the foot hills up to the high elevation scree slopes on dry mountain ranges. It's domain encompasses five western states CA, ID, NV, OR, UT, WA. This Penstemon is found in scattered populations throughout the Great Basin Floristic Province. The species is common in western UT, southern ID, and all of NV. It can also be found along the eastern Cascade and Sierra Nevada ranges of Washington, Oregon and California.
Penstemon speciosus is variable in appearance. Lower elevation forms have an open airy appearance, with greener coloration to the leaves. The higher forms are low, condensed with denser inflorescence,and a gray cast to the foliage. At altitudes of around 8000'-9000' around Lake Tahoe I have come across very dwarf forms may be six inches tall with gray foliage. Flower color varies some but blue through blue/violet are what I encounter most often. I do have one plant that has a pink hue.

The first shot is of a lower elevation form.
Number two a mid elevation form.
Number three the pink plant
The rest close ups of the flowers.
Last a high elevation dwarf form.


Submitted by Mark McD on Wed, 05/26/2010 - 20:32

John, a gorgeous Penstemon, when in its best form.  Your series of photos and explanation of plant differences relative to altitude is a good lesson on plant variability, some forms are much better than others, and it is always worth trying the same species several times to find the best and most pleasing ones.  The common names for this pent seem appropriate.  I like the mid elevation dense-inflorescence types best based on your photos.

Beautiful John. The dwarf forms led me to read up Nicholls "Alpine Plants of North America" and he says Penstemon speciosus ssp. kennedyi is the name "commonly given to dwarf specimens, and although not all references recognise it as a separate subspecies, perhaps they should since it remains dwarf in cultivation...." The Plant List recognises it. Nicholls gives the range of ssp. kennedyi as 10,175-11,700ft in the Sierra Nevada and White Mountains of California on rocky volcanic slopes and open summit ridges of gritty granite soils. Is this your experience too? 

I have found it growing at about 9600" elevations on Slide Mountain and Mount Rose in Washoe County, NV (between Reno and Lake Tahoe) It is all commonly four to six inches tall with bright blue flowers. At 4,000' in my garden it will reach six to eight inches tall. At high elevation it is has to endure considerable wind so is shortened. The leaves are also much grayer than the lower elevation populations.