Penstemon atwoodii is a narrowly distributed species endemic to Utah, which is found only on the Kaiparowits geological formation between 1650 – 2100 m (6200 – 8000 ft). It was described in 1975 by Stanley L. Welsh, and is named in honor of Nephi Duane Atwood, described as a “student of Hydrophyllaceae, field botanist extraordinary, and first to recognize the unique nature of this taxon” (Welsh 1975). I met this charming species during the 2014 American Penstemon Society meeting, which was held in Springdale, Utah.
Penstemon atwoodii is a member of subgenus Penstemon section Cristati. The plant is glandular pubescent, with relatively small flowers (13–16 mm long; just over 1/2 inch). The opening of the corolla has long vertical hairs growing on the palate, which become flattened after the flower is visited by pollinators.
The plant is not considered to be endangered at present by any federal or state agency, and is not yet in cultivation. I think it would be a lovely rock garden plant, though, and should be given some attention by members of the American Penstemon Society.
I find plants such as P. atwoodii intriguing in that it is found only on a particular geological substrate. The Kaiparowits formation is mudstone, originating in the late Cretaceous time period. You can see from this habitat shot, that the population I visited was in a gravelly spot:
The plant is very leafy and is 12.7–40.6 cm (5–16 inches) in height while in flower.
Here are some other photos from this population:
Welsh SL (1975) Utah plant novelties in Cymopterus and Penstemon. Great Basin Naturalist 35, 377-378.