I thought this might give you and others insight as to Penstemons in the US.
This text is copied via Paperport from my brand new edition of the Sunset Western Garden Book. The revision of the book supposedly took 10 years to complete. They added quite a few new varieties of plants and also added colored photos, where in my previous issue they used artist's drawings to depict them.
After this data, the book listed about 30 species that are out here someplace in the Western US.
Whether we came upon any varieties when on our hikes into the wilds, I don't know. We'll be on the lookout for any from now on.
'Most of the approximately 250 species of penstemon are native to the West, ranging from Canada into Mexico. Some grow on highest mountains, some in the desert, others in forest glades, in foothills, on plains. A few are widely available, but most are sold only by specialists. Most species have narrowish, pointed leaves; those in basal foliage clump are larger, those on flower stems smaller. Narrowly bell-shaped, lipped flowers (usually /4-11/2 in. long) are most commonly seen in bright reds and blues, but they also come in shades from soft pink through salmon and peach to deep rose, lilac, dark purple, white, and, rarely, yellow.
All penstemons, but especially the wild species, need fast-draining soil. Plants are fairly short-lived (3 or 4 years). Hybrids and selections tend to be easier to grow than wild species alongside regular garden plants; wild kinds may die quickly if given too rich soil and too much water. In dry years or with restricted water, however, plants of wild species may thrive.'
- Toby
