Scrophulariaceae (The Figwort Family)
What's in a Name?
It's most often told that "penstemon" is from the Greek for five stamens, but the word may actually be derived from the Latin for "almost a thread (stamen)," in reference to it's sterile fifth "staminode". And while the new family, Plantaginacea (more on all this later...), is from Plantago (L. "plantain"), the Scrophulariaceae family has a much more interesting naming story.
Now, a word about names.
Am I allowed to love etymology and loathe taxonomy?
|Meriwether Lewis' 1806 specimen|
I learned the Penstemon species when they were in the Scrophulariaceae family, as they have been for 150 years. For me, penstemon is the poster-child scroph, with its puckered, pouty lips. In my heart, this is where they belong, alongside the monkeyflowers and blue-eyed marys. But while the sport of taxonomy is full of mysteries and stories of its own, it's also a notorious pain in the ass. Full of unpronounceable, impossible to remember words that are always changing. For a word-romantic like myself it could be maddening, if not for this simple, secret coping mechanism: I just ignore it. It's very un-scientific of me, I know, and very stubborn. But as far as I'm concerned, penstemons are figworts and not plantains and in my heart of hearts, there they shall remain. Molecular phylogenies be damned.
There is a bit of variation in this genus, but the flowers are distinct. Most are shades of purple, some leaning more towards blue or pink (even red). White flowers are pretty common too, and there are a couple of yellow species. All have five petals, fused into a tube at the base and flared out into two upper and three lower lips at the ends. Inside the tube you'll find five stamens--one sterile (the staminode), the other four bearing anthers. The plants are usually anywhere from 3" to 30" tall, some woodier than others, with simple, opposite leaves growing in clusters near the base of flower stalks.
Penstemon is the largest genus of flowering plants in North America with over 270 species. Thirty-six of them are listed in Montana, with many of these designated as "species of concern" and only found in very localized areas. They are also commonly called beardtongues. Flowers in the genus Keckiella, found in the southwest, are also commonly known as penstemons or beardtongues, and are actually the progenitors of the Penstemon genus we have today. The ones I encounter most often in western Montana are Wilcox (P. wilcoxii), small blue (P. procerus) and fuzzytongue (P. eriantherus). They're easy to tell apart, although you might encounter plants that look very similar to each that are a different species entirely.
In general, Wilcox penstemon is the classic, tall, super showy blue-lipped flower that you see all over rocky slopes just about the time the larkspur are beginning to fade. They form basal rosettes of glabrous (hairless), narrow eye-shaped leaves, a couple inches long, that tend towards a reddish-purple edge. Flower stalks generally reach ~12-18", but can be over two feet tall if the plants have access to more water. The flowers are light-bluish to deep purple and are just stunning.
The small-flowered, somewhat woody Penstemon procerus is also common, with its stalks standing at attention. You'll find this one in wetter places like meadows and gullies. The plants and individual flowers are about 1/3 - 1/2 the size of the larger Wilcox variety, and tend to be darker shades of purple. The leaves are also much more narrow and lanceolate.
Fuzzytongue penstemon is a knockout--one of my all-time favorites. It's soft, small, and has a mesmerizing flower. The tube formed by the petals is cavernous and very mouthlike, with the four anther-bearing stamens curved like fishbones around the bearded tongue of the fifth sterile stamen. They grow in the toughest of conditions, on the driest, highest, windiest mountains. They're incredible.
Penstemon is a snap to grow and propagate, thriving in difficult soils, drought and heat. The many-seeded fruit capsules are easy to collect. When the capsules start to split open the seeds are ready; just cut off the stalks and collect them in paper bags. These plants need cool moist stratification to germinate, so either sow seeds outdoors in fall, or in pots that will be left outside for the winter. Once the leaves are up they transplant well, and are perfect rock garden specimen plants for an early summer show of color. And the bees adore them. I've spent many hours in my backyard watching the hubbub of activity around the Wilcox' penstemon in particular. On a sunny afternoon, you're guaranteed to find dozens of native bees happily dipping their heads into each purple tube for a sip of nectar.
For a ton more information on growing penstemon, check out Susan Greer's Native Penstemons in our Gardens. If you want to dig deeper, don't miss Myrna Jewett's really great article about growing shrubby beardtongues for rock gardens, with additional insight into the North American evolution of the Penstemon genus. In it, she points out that penstemons are shifting slightly toward being hummingbird-pollinated, with an interesting discussion on why that might be.