familyPlantaginaceae
genusPenstemon
subgenusPenstemon subg. Penstemon
sectionPenstemon sect. Cristati
speciesPenstemon laricifolius
Penstemon laricifolius var. exilifolius
Univ. Wyoming Publ. Sci., Bot. 1: 97. 1924.
IllustratedEndemic
Basionym: Penstemon exilifolius A. Nelson Bull. Torrey Bot. Club 28: 230. 1901
Synonyms: P. laricifolius subsp. exilifolius (A. Nelson) D. D. Keck
Flowers: corolla white, 9–15 mm.
Phenology: Flowering Jun–Aug.
Habitat: Sandy or gravelly grasslands, sagebrush shrublands.
Elevation: 1500–2900 m.
Discussion
Variety exilifolius is concentrated in the Laramie Basin of Wyoming and Laramie River Valley of northwestern Larimer County, Colorado. Other isolated populations are known in Wyoming (B. L. Heidel and J. Handley 2007). A specimen from southern Montana, reported by Heidel and Handley, could be this variety; the specimen has not been seen for this study.
Lower Taxa
None.