11) Penstemon and other Scrophulariaceae

Sometimes Penstemon barbatus and Penstemon eatoni get confused, both being tall scarlet-flowered penstemons. I don't currently have a good photograph of Penstemon barbatus, but I'm showing a couple photos of Penstemon eatonii taken in my garden in 2009.

This one is in bloom now. I keyed it out last year as Penstemon secundiflorus, I thought, based on what's visible in the attached photos (pardon the dirty fingers in the pix!) as well as:
- calyx glabrous, entire to slightly erose
- staminode exerted, expanded to 3mm at the tip, densely bearded to 1/2 its length, mainly on the edges, with long tangled yellow hairs

Some years ago along an Arizona highway in the middle of nowhere, I saw Penstemon ambiguus in bloom and fell instantly in love. The clumps were scattered and about 18" high in full bloom. After taking many pictures (all slides, alas), I carefully noted the kind of soil in which it grew (sand, old sparkplugs, shredded bits of rubber from tire blowouts, sand, cigarette stubs). I grew it from seed and ended up with half a dozen seedlings ready to plant. They were planted in different spots in the garden. Three died quite quickly when we had rain on and off for several weeks.

A long drive across the prairies last weekend was enlivened a bit for me as I stopped to look at some roadside plants... here is white beard-tongue, Penstemon albidus, a little colony in bloom, in west-central Saskatchewan.
The glandular nature (i.e. having glands that exude a sticky or oily substance) of the inflorescence is made clear by all the tiny bugs and little bits of what-not stuck to it, visible in some of the photos!

I've been growing this little linear-leaf Penstemon for a few years in a trough, purchased from a New England grower of rock plants. It's not very showy, a few stems with a few tubby violet flowers at a time, never many flowers at once but stretched out over a few weeks. The stems reach about 8" tall. The plant does not match photos I've seen on the USDA site, which I include links for comparison... the leaves on my plant much too narrow compared to USDA photos (see below), and as well, the USDA photos shows flowers spaced much more densely along the stem in congested manner.

I bought two P. fasciculatus plants at the Denver Botanic Garden sale last month and hope to put them in the ground today. Turns out the color is inappropriate for the intended location and I'm considering a couple of other ones.

Where does this penstemon grow? Soil? Elevation? Solar aspect?

Any help is appreciated.

The native Penstemon on my property is P. jamesii. A white one started opening today. It is quite striking and I'd like to propagate it. Does anyone have experience self-fertilizing penstemons? Should I isolate it with shade cloth? Try fertilizing it with a paint brush? Am I likely to develop a white seed strain? Should I just let the bees do their thing?

I've noticed that some Penstemons aren't self-fertile, so am apprehensive about interfering in the process. :-\

Thanks!

In my continuing saga of mis-ID'd penstemons, here's the offspring of some seed (not from the NARGS exchange) labeled P. heterophyllus. I grew that one before, and am pretty sure this is something different. It resembles the P. venustus I grew more recently, although these new plants are bigger; they were evergreen (or greened up early in spring) in my zone 6 garden, and tended to lay themselves down, rooting along the stem. I like it.

So here's another penstemon which is almost certainly misidentified in our garden (of all genera, it seems like penstemon has given me the most misidentified plants from seed trades and society exchanges!)
It came to me as P. caryi, but the foliage looks nothing like the image at http://apsdev.org/identification/descriptions.php?whichspecies_name=caryi . Any suggestions what I have on my hands?
Thanks in advance,
Rob

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.