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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: The inflorescence is glandular pubescent, and the shape of the corolla is ampliate (very expanded past the tube).

Penstemon atwoodii: The inflorescence is glandular pubescent, and the shape of the corolla is ampliate (very expanded past the tube).

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:

Not the friendliest habitat for taking photos - it's hard to kneel on gravel...

Not the friendliest habitat for taking photos – it’s hard to kneel on gravel…

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:

20140520-5D_37024-©2014_Andi_Wolfe_-_all_rights_reserved

The inflorescence is nearly secund – the flowers face mostly in one direction.

Leaves and stem - this species has a basal rosette that is persistent.

Leaves and stem – this species has a basal rosette that is persistent.

The corolla opening is nearly blocked by hairs on the staminode and palate. I wonder if this is a signal mechanism to let a bee know the flower hasn't been visited.

The corolla opening is nearly blocked by hairs on the staminode and palate. I wonder if this is a signal mechanism to let a bee know the flower hasn’t been visited.

There are nectar guides in the form of purple lines - very obvious in this light.

There are nectar guides in the form of purple lines – very obvious in this light. Notice that the hairs on the palate are flattened in these flowers.

Literature cited

Welsh SL (1975) Utah plant novelties in Cymopterus and Penstemon. Great Basin Naturalist 35, 377-378.

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