title: Molecular and morphological evidence for Penstemon luculentus (Plantaginaceae): a replacement name for Penstemon fremontii var. glabrescens.
abstract: Penstemon luculentus R.L.Johnson & M.R.Stevens, nom. nov. replaces Penstemon fremontii var. glabrescens Dorn & Lichvar. The varietal name glabrescens was not elevated because it was already occupied by Penstemon glabrescens Pennell, a different species. This new arrangement is supported by molecular and morphological evidence. An analysis of genetic diversity in populations of both varieties of Penstemon fremontii Torr. & A. Gray (glabrescens and fremontii) from the Piceance Basin, Colorado, using SSR (simple sequences repeats) or microsatellites markers, revealed significant genetic differentiation between the two. Penstemon fremontii var. glabrescens was also genetically different from Penstemon gibbensii Dorn and Penstemon scariosus var. garrettii (Pennell) N.H. Holmgren. The combination of hirtellous stems, glabrous leaves, non-glandular inflorescence, and long anther hairs distinguish Penstemon luculentus from other morphologically similar species.
authors.affiliation: Department of Biology, Brigham Young University, 3115A Monte L. Bean Museum, Provo, Utah 84602 USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnson
authors.affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, 5131 Life Sciences Building, Provo, Utah 84602 USA.
authors.forename: Mikel R
authors.initials: MR
authors.lastname: Stevens
authors.affiliation: Department of Biology, Brigham Young University, 3115A Monte L. Bean Museum, Provo, Utah 84602 USA.
authors.forename: Leigh A
authors.initials: LA
authors.lastname: Johnson
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Forage and Range Research Laboratory, 690 N. 1100 E., Logan, Utah 84322 USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Robbins
authors.affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, 5131 Life Sciences Building, Provo, Utah 84602 USA.
authors.forename: Chris D
authors.initials: CD
authors.lastname: Anderson
authors.affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, 5131 Life Sciences Building, Provo, Utah 84602 USA.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Ricks
authors.affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, 5131 Life Sciences Building, Provo, Utah 84602 USA.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Farley
keywords: Colorado; Penstemon; Piceance; Rio Blanco; White River Shale