Penstemon debilis

Plant Information
Species: 
debilis
Species Authority: 
O'Kane & J.L. Anderson
Subgenus: 
Habroanthus
Section: 
Glabri
Habit:
 
robust herb
Habit Woodiness:
 
herbaceous
Lifespan: 
long-lived
Habitat Description: 
Oil shale talus of the Green River formation.
Distribution Range: 
Colorado, United States. Garfield County: Roan Cliffs, south side of Mount Callahan, west to southwest of Parachute on steep south exposure of Green River shale.
Soil Type: 
Oil shale talus.
Elevation - Min: 
2500.00m
Elevation - Max: 
2500.00m
Other Notes: 

Field recognition characters for Penstemon debilis are its weak stems (hence the specific epithet), soboliferous habit, succulent, glabrous, and glaucous leaves, and its white to pale lavender corollas. Although corolla color and leaf apices vary, the entire range of variability is often represented on a single plant. The species has been listed as Federally Threatened. The Wolfe Lab did a conservation genetics study for this species: Wolfe AD, McMullen-Sibul A, Tepedino VJ, Kubatko L, Necamp T, Fassnacht S (2014) Conservation genetics and breeding system of Penstemon debilis (Plantaginaceae), a rare beardtongue endemic to oil shale talus in western Colorado, USA. Journal of Systematics and Evolution 52:597-611 do:10.1111/jse.12100.

Photos by Andi Wolfe ©1998 - All rights reserved.

First Bloom: 
June
Last Bloom: 
May
References: 
O'Kane SL, Anderson JL. 1987. Penstemon debilis (Scrophulariaceae), a new species from Colorado endemic to oil shale. Brittonia. 39(4):412-416.