I previously shared a few common garden Penstemon in this post. Yesterday, I was watching a talk on Penstemon by Dr. Andi Wolfe (Ohio State University) and she has some beautiful slides. Please enjoy this look at Penstemon diversity.
Penstemon is the largest genus endemic to North America — over 250 species, plus a steady run of named cultivars — so if you grow more than a couple it’s worth marking which is which. The three here do stay distinguishable out of bloom if you know the foliage: Palmer’s is glaucous blue-grey with perfoliate leaves that fuse around the stem, Rocky Mountain holds a dense evergreen basal rosette, and Beardlip is narrower-leaved and looser in habit. It’s the cultivar names that vanish. And since these three sit in different sections and don’t readily cross in the garden, a self-sown seedling usually comes true — so a marker on the parent tells you what the volunteer is as well. I engrave weatherproof markers with the common and botanical name, and a third line for the cultivar or the year it went in. See the native plant markers →
