Filters
Penstemon arkansanus Pennell
Penstemon attenuatus Douglas
Penstemon auriberbis Pennell
Penstemon azureus Benth.
Penstemon barbatus (Cavanilles) Rothrock
Penstemon barbatus (Cavanilles) Rothrock 'Praecox Nanus'
Penstemon barrettae Gray
Penstemon buckleyi Pennell
Penstemon caespitosus Nutt. ex A. Gray.
Penstemon campanulatus (Cav.) Willd.
Penstemon cardwellii T. J. Howell.
Penstemon centranthifolius (Benth.) Benth.
Penstemon cinicola Keck
Penstemon confertus Douglas
Penstemon davidsonii Greene
Penstemon davidsonii Greene var. menziesii (D.D.Keck) Cronquist
Penstemon deustus Douglas
Penstemon digitalis Nutt.
Penstemon discolor Keck.
Penstemon duchesnensis (N.H. Holmgren) Neese
Penstemon eatonii A. Gray var. exsertus (A.Nelson) C.C.Freeman
Penstemon eatonii A. Gray ssp. undosus (M.E. Jones) Keck
Penstemon eriantherus Nutt. ex Pursh
Penstemon euglaucus English.
Penstemon floridus Brandeg. var. austinii (Eastw.) N. Holmgren
Penstemon fruticosus (Pursh) Greene
Penstemon fruticosus (Pursh) Greene var. scouleri (Lindley) Cronquist
Penstemon glaber Pursh var. alpinus (Torr.) A.Gray
Penstemon gormanii Greene
Penstemon grinnellii Eastw. var. scrophularioides (M.E. Jones) N.H. Holmgren