The world of Wyoming Penstemons is a whirlwind of pinks, purples, and blues. They intrigue me because they grow and blossom in some of the most inhospitable soils Wyoming can dish out; sand, rock, clay, windswept hillsides, fully exposed southern faces. Their ability to beautify the extremely inhospitable is always a wonderful surprise, and they don’t do it with a shy, humble approach – they do it with bravado!
One of the spectacular examples of a true blue flower is a Penstemon that grows on blow-out sandhills. It is as blue as our Wyoming skies. Penstemons can be hard to positively identify, but I believe the one I have found and collected is Penstemon angustifolius.
Two other Wyoming native Penstemons have graced my garden. I no longer have this garden, so I cannot positively identify them, but my best guess for the tall one is P. strictus.
Wyoming Life 
These are great plants. If you catch the flowers in the right like, the color can appear iridescent. And, as you indicate, the places they grow are often surprising, bringing color to otherwise drab landscapes.
@ Ken, and we aren’t alone in appreciating this genus. The American Penstemon Society has a healthy membership. They also have great information on their website at http://apsdev.org/welcome.html
I took a look at their website, and they seem to be a passionate bunch! We are in the process of sprucing our place up with some plants and shrubs, and we’ll be trying to get some penstemon established also.
For me, Penstemon strictus is one to try. I have started some from two year old seed this year and I had good germination. They are easy. Hopefully I will be able to nurture some along to maturity. If I am successful, I will be able to share some seeds next year. I’d be happy to send some your way. My original source has been taken out by highway expansion.
Another one I would want to try is P. fruticosus because of it size and shape and tolerance for a wider range of conditions (as far as western Penstemons go). I have seen some photos of it in its natural environment… small shrubs covering rocky areas… stunning. This link might help you decide if it would work for you.
http://www.uwyo.edu/wera1013/plantlist_penstemonfruticosus.asp
I’ll be posting an article with some more shots of “Penstemons I Have (Only) Known” soon.
Happy sprucing up!