Scottish Rock Garden Club Forum

Plant Identification => Plant Identification Questions and Answers => Topic started by: Philippe on December 11, 2010, 09:57:42 AM

Title: Penstemon and eriogonum identification
Post by: Philippe on December 11, 2010, 09:57:42 AM
Hi

Two north american plants of which I'm more or less unsure.
If anyone could help.
For the penstemon, I received it under P.campanulatus. No doubt it is not P.campanulatus.
After having searched in books and on the web, I found P.crandallii could be a better solution. But still not the good one in my opinion, as the leaves in P.crandallii look different as on my pic ( perhaps a subspecies, or even a garden-hybrid?)
The flowers, when opened, are of a really lovely blue. The plants in foliage is not taller than 2 or 3 cms high, and the flowering stems shoot up to 5 to 10 cms high
It can't get yet into the collection viewable by the visitors, because of its unnamed status.

I think the second one is probably eriogonum ovalifolium. It's very low, not more than 2 or 3 centimetres deep in the middle of the cushion. The flowers tend to lay down on the floor on elongating stems as they progressively get passed.
I just know that there can be some var.of it, perhaps anyone will recognize one of them, or it might simply be the normal sp.ovalifolium

Thank you!
Title: Re: Penstemon and eriogonum identification
Post by: Graham Catlow on December 11, 2010, 10:38:15 AM
Hi Philippe,
The Penstemon looks like a Penstemon procerus to me - perhaps var. brachyanthus or on second thoughts var. formosus

Title: Re: Penstemon and eriogonum identification
Post by: Philippe on December 11, 2010, 11:10:38 AM
Hi Philippe,
The Penstemon looks like a Penstemon procerus to me - perhaps var. brachyanthus or on second thoughts var. formosus



Yes, it really does!
Thank you, I will look closer next year to try to find out the var. it could eventually be.
Title: Re: Penstemon and eriogonum identification
Post by: TheOnionMan on December 11, 2010, 01:07:07 PM
The penstemon is indeed P. procerus var. fomosus, commonly distributed for decades in the UK under the misidentification of either P. campanulatus (Mexican species, 1 meter tall, purple) or as P. "pulchellus" (syn: Penstemon campanulatus ssp. chihuahuensis, also tall).
https://listserv.surfnet.nl/scripts/wa.cgi?A2=ind0003&L=ALPINE-L&P=R10264

Not sure on the Eriogonum, they are devilishly difficult to key.
Title: Re: Penstemon and eriogonum identification
Post by: Lesley Cox on December 11, 2010, 08:02:20 PM
These are two of my favourite American genera and I wish there were more pictures and more information about them here on the Forum. I have very few of either but would love to learn more from this source, as well as from the American seedlists.
Title: Re: Penstemon and eriogonum identification
Post by: TheOnionMan on December 11, 2010, 08:54:14 PM
Lesley, for Eriogonum you might want to take a look at the NARGS Forum, there are a couple individuals there are quite expert with the genus, and they're off to a good start highlighting a number of species. These individuals live in areas where Eriogonums grow natively. Take a look here at the Eriogonum board:
http://nargs.org/smf/index.php?board=15.0

When the forum opens up for posting by registered internet users in early 2011, maybe we'll so you there.
Title: Re: Penstemon and eriogonum identification
Post by: Maggi Young on December 11, 2010, 09:15:06 PM
Mark's right, there are several threads to delight you on those plants ( and more!) in the NARGS .

Also, In the last two issues #10 and #11 of International Rock Gardener  there have been some cracking examples of Eriogonum and Penstemon....

http://www.srgc.org.uk/logs/index.php?log=international

 and there are links to the specialist societies of both, too- as there are on the links pages of the Forum...
http://www.apsdev.org/

http://www.eriogonum.org/

Title: Re: Penstemon and eriogonum identification
Post by: Philippe on December 12, 2010, 10:27:11 AM
Thanks Mark and Maggi for your links ;)
Title: Re: Penstemon and eriogonum identification
Post by: Darren on December 17, 2010, 03:08:18 PM
At a show this spring I had a conversation with both a current and a former nurseyman about this Penstemon. They have the same experience as me (which is reassuring!) in that it flowers well the year after planting but thereafter forms a nice healthy mat of leaves but never a flower. 5 years since i saw a flower on my plant. I've tried extra feeding to no avail. Any ideas or similar experiences?

Title: Re: Penstemon and eriogonum identification
Post by: Philippe on December 17, 2010, 03:58:34 PM
If it really doesn't flower well after having planted it, although staying in the same general weather conditions, there might be something about the soil? Too rich, roots have place and take the soil nutrients to favour "green" growth?
But it should have been pointed it out anyway in this case, it's one of the first, if not the first thing that comes in mind.
My penstemon grows and flowers very well every year, and I don't do anything special at all for the moment ( soil is a mix of sand, grit/ some clay and silt ( not sure those are the good words for what I exactly mean). No leaf mould, loam, or so, nothing vegetal.
But I have to say it spends most of the winter under a thick snowcover. This may also have an influence, I don't know.
Title: Re: Penstemon and eriogonum identification
Post by: TheOnionMan on December 17, 2010, 04:56:02 PM
At a show this spring I had a conversation with both a current and a former nurseyman about this Penstemon. They have the same experience as me (which is reassuring!) in that it flowers well the year after planting but thereafter forms a nice healthy mat of leaves but never a flower. 5 years since i saw a flower on my plant. I've tried extra feeding to no avail. Any ideas or similar experiences?


Darren, Philippe's cultural notes are on target.  One of the prime rules of Penstemon (with the exception of the tall, blousy, mostly English-bred Mexican type of border-perennial penstemon) is that the species should never be fed, in fact you can kill them with kindness.  My Penstemon procerus var. formosus flowers every year, but not always as well in some years, this year and last year it flowered only modestly (photo in 2009, sorry but it is a bit blurry).
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