Penstemon fruticosus v scouleri Albus

Submitted by Sellars on Tue, 08/24/2010 - 20:56

We found this white Penstemon on Mt Kobau in the Southern Okanagan, British Columbia, last June. Can anyone confirm that it is Penstemon fruticosus v scouleri Albus?

I took a few cuttings and have several plants growing-on quite well.


Submitted by Mark McD on Thu, 08/26/2010 - 13:33

Yes David, that looks like Penstemon fruticosus var. scouleri to me, and a very fine form it is.  The giveaway characteristic are the leaves which are decidedly narrow and entire (not noticeably serrate).  The flowers certainly are large in proportion to the leaves.  Notice that I did not call it Albus, as there is no such valid taxonomic epithet. Although in the past there is a widely known white flowered selection of this penstemon named 'Albus', an early latinized cultivar name that doesn't comply with today's International Code of Botanical Nomenclature and by rights should be renamed, although such names are so entrenched in horticulture they're hard to change and are best lived with or tolerated.  There's a photo of that plant in Bob Nold's Penstemons, taken of plants growing in my garden when I lived in Washinghton State back in the early 1980s.  

It is probably best to refer to the plant as Penstemon fruticosus var. scouleri "White Form", or possibly if you believe it worthy of a cultivar name, supply a new name for it such as Penstemon fruticosus var. scouleri 'Mount Kobau White' or something like that.  Glad your cuttings faired well, be sure to eventually share some with the horticultural world if you're successful.

Nice find!

Submitted by RickR on Thu, 08/26/2010 - 16:15

A worthy plant ideed, whatever the name is!

McDonough wrote:

Although in the past there is a widely known white flowered selection of this penstemon named 'Albus', an early latinized cultivar name that doesn't comply with today's International Code of Botanical Nomenclature and by rights should be renamed

Cultivars named before 1959 are latinized, according to today's International Code of Nomenclature for Cultivated Plants (ICNCP). After 1958, all cultivar names are "Fancy names" and not latinized.  They can be any language except Latin.
So if Albus was designated prior to 1959 it is currently legal.

By the way, there are more rules for naming cultivars.

Of course, the botanists of the International Code of Botanic Nomenclature (ICBN) would have none of this.  For them, the albus would either be absorbed into the variety scouleri, or be differentiated as a form (Penstemon fruticosis var. scouleri f. albus).  There are no cultivar names under ICBN rules.

Submitted by Sellars on Fri, 08/27/2010 - 10:26

Mark and Rick:

Thanks for your comprehensive replies.  Here is a photo of one of the cuttings showing the narrow leaves which are only slightly serrate.  The cuttings took very easily and the growth is vigorous (with roots already appearing at the base of the pot).  I would be happy to share it. 

Submitted by Sellars on Mon, 05/14/2012 - 21:40

The cutting from the plant on Mount Kobau has taken happily to the garden and has lovely flowers this spring.  Unlike many alpine plants, it seems to flower better in the garden than in the wild.

Submitted by Weiser on Wed, 05/16/2012 - 11:53

Very nice form and color.

I only grow the standard hot pink form. Mine experience die back every two to three years, on older woody branches. Have you had these planted out doors long enough to notice similar behavior?

Submitted by Sellars on Fri, 05/18/2012 - 07:36

Thanks Mark.

I have not grown Penstemon fruticosus v scouleri before but Penstemon fruticosus 'Purple Haze' is a very good plant in the garden.  We have had it for about 10 years and it propagates easily. It was selected at the University of British Columbia.

Submitted by Mark McD on Fri, 05/18/2012 - 08:24

The name Penstemon fruticosus 'Purple Haze' implies it is a floriferous selection, would like to see a photo sometime.  This reminds me of my days living near Seattle, getting up into the Cascade Mountains & the Wenatchees, and one finds lots of variability with Penstemon fruticosus. I selected a very pale form that was near white with a tinge of lilac, I was able to root plants from cuttings.  This is all but a distant memory at this point.

Submitted by Sellars on Fri, 05/18/2012 - 22:06

Purple Haze is indeed very floriferous.  We had a large clump that was covered in flowers.  It can be seen in the first photo at the edge of the rock garden on the right.  The second photo is a zoom in to that plant and the third photo shows the view of the rock garden from the other side with the plant to the left above the boulders lining the lawn.

This plant was so successful that it became too dominant and we have since reduced its size  :D

Submitted by RickR on Sat, 05/19/2012 - 08:56

Spectacular... and wondrous and glorious!
  The rock construction, not to mention the plants, is expertly done. :o

Gosh, it would be nice if my pensteomons bloomed like that!

Submitted by Peden on Sat, 05/19/2012 - 15:16

I agree about David Sellars yard: spectacular and encouragement to us all. Mark; Isn't P. 'Wax Works' one of your plants? This all comes 'round because I lost my 'Wax Works' two or three years ago, but last year noticed seedlings, and these have returned, that look a lot like 'Wax Works' children. I'm not completely up to speed on my Penstemon growing yet; but these are being closely watched.

Submitted by Sellars on Sat, 05/19/2012 - 23:00

Thanks for your kind comments on our garden.

Those pictures with the Penstemon fruticosus Purple Haze were taken 8 years ago! This is what the garden looks like today.  We've finally had a sunny spell of good weather. 8)

Submitted by Booker on Sun, 05/20/2012 - 10:08

What an absolute joy to stroll through your magnificent garden, David - with a camera, a plantsman's eye and a photographic memory to record and remember every horticultural delight. Truly superb.