| Arten: |
| Penstemon abietinus Pennell |
| Penstemon absarokensis Evert |
| Penstemon acuminatus Dougl. ex Lindl. |
| Penstemon alamosensis Pennell & Nisbet |
| Penstemon albertinus Greene |
| Penstemon albidus Nutt. |
| Penstemon albomarginalis M. E. Jones |
| Penstemon albomarginatus M.E. Jones |
| Penstemon alluviorum Pennell |
| Penstemon ambiguus Torr. |
| Penstemon ammophilus N. Holmgren & L. Shultz |
| Penstemon anguineus Eastw. |
| Penstemon angustifolius Nutt. ex Pursh |
| Penstemon arenarius Greene |
| Penstemon arenicola A. Nels. |
| Penstemon aridus Rydb. |
| Penstemon arkansanus Pennell |
| Penstemon attenuatus Dougl. ex Lindl. |
| Penstemon atwoodii Welsh |
| Penstemon auriberbis Pennell |
| Penstemon australis Small |
| Penstemon azureus Benth. |
| Penstemon baccharifolius Hook. |
| Penstemon barbatus (Cav.) Roth |
| Penstemon barnebyi N. Holmgren |
| Penstemon barrettiae Gray |
| Penstemon bicolor (Brandeg.) Clokey & Keck |
| Penstemon bracteatus Keck |
| Penstemon breviculus (Keck) Nisbet & R.C. Jackson |
| Penstemon bryantiae Keck |
| Penstemon buckleyi Pennell |
| Penstemon caesius Gray |
| Penstemon caespitosus Nutt. ex Gray |
| Penstemon calcareus Brandeg. |
| Penstemon californicus (Munz & Johnston) Keck |
| Penstemon calycosus Small |
| Penstemon campanulatus (Cav.) Willd. |
| Penstemon canescens (Britt.) Britt. |
| Penstemon cardinalis Woot. & Standl. |
| Penstemon cardwellii T.J.Howell |
| Penstemon carnosus Pennell |
| Penstemon caryi Pennell |
| Penstemon centranthifolius Benth. |
| Penstemon cinicola Keck |
| Penstemon cleavelandii Gray |
| Penstemon clevelandii Gray |
| Penstemon clutei A.Nels. |
| Penstemon cobaea Nutt. |
| Penstemon comarrhenus Gray |
| Penstemon compactus (Keck) Crosswhite |
| Penstemon concinnus Keck |
| Penstemon confertus Dougl. ex Lindl. |
| Penstemon confusus M.E. Jones |
| Penstemon crandallii A.Nels. |
| Penstemon crideri A.Nels. (pro sp.) |
| Penstemon cusickii Gray |
| Penstemon cyananthus Hook. |
| Penstemon cyaneus Pennell |
| Penstemon cyanocaulis Payson |
| Penstemon cyathophorus Rydb. |
| Penstemon dasyphyllus Gray |
| Penstemon davidsonii Greene |
| Penstemon deamii Pennell |
| Penstemon deaveri Crosswhite |
| Penstemon debilis O'Kane & J.Anderson |
| Penstemon degeneri Crosswhite |
| Penstemon deustus Dougl. ex Lindl. |
| Penstemon digitalis Nutt. ex Sims |
 |
| Penstemon diphyllus Rydb. |
| Penstemon discolor Keck |
| Penstemon dissectus Ell. |
| Penstemon distans N.Holmgren |
| Penstemon dolius M.E.Jones ex Pennell |
| Penstemon dubius A.Davids. (pro sp.) |
| Penstemon eatonii Gray |
| Penstemon elegantulus Pennell |
| Penstemon ellipticus Coult. & Fisher |
| Penstemon eriantherus Pursh |
| Penstemon euglaucus English |
| Penstemon eximius Keck |
| Penstemon fendleri Torr. & Gray |
| Penstemon filiformis (Keck) Keck |
| Penstemon flavescens Pennell |
| Penstemon floribundus D.Danley |
| Penstemon floridus Brandeg. |
| Penstemon flowersii Neese & Welsh |
| Penstemon franklinii Welsh |
| Penstemon fremontii Torr. & Gray ex Gray |
| Penstemon fruticiformis Coville |
| Penstemon fruticosus (Pursh) Greene |
| Penstemon gairdneri Hook. |
| Penstemon gibbensii Dorn |
| Penstemon glaber Pursh |
| Penstemon glandulosus Dougl. |
| Penstemon glaucinus Pennell |
| Penstemon globosus (Piper) Pennell & Keck |
| Penstemon goodrichii N.Holmgren |
| Penstemon gormanii Greene |
| Penstemon gracilentus Gray |
| Penstemon gracilis Nutt. |
| Penstemon grahamii Keck |
| Penstemon grandiflorus Nutt. |
| Penstemon griffinii A.Nels. |
| Penstemon grinnellii Eastw. |
| Penstemon guadalupensis Heller |
| Penstemon hallii Gray |
| Penstemon harbourii Gray |
| Penstemon harringtoni Penl. |
| Penstemon harringtonii Penl. |
| Penstemon hartwegii Benth. |
| Penstemon havardii Gray |
| Penstemon haydenii S.Wats. |
| Penstemon heterodoxus Gray |
| Penstemon heterophyllus Lindl. |
| Penstemon hirsutus (L.) Willd. |
| Penstemon humilis Nutt. ex Gray |
| Penstemon idahoensis Atwood & Welsh |
| Penstemon immanifestus N.Holmgren |
| Penstemon incertus Brandeg. |
| Penstemon inflatus Crosswhite |
| Penstemon jamesii Benth. |
| Penstemon janishiae N.Holmgren |
| Penstemon jonesii Pennell |
| Penstemon kingii S.Wats. |
| Penstemon labrosus (Gray) Hook. |
| Penstemon laetus Gray |
| Penstemon laevigatus Ait. |
| Penstemon laevis Pennell |
| Penstemon laricifolius Hook. & Arn. |
| Penstemon laxiflorus Pennell |
| Penstemon laxus A. Nels. |
| Penstemon leiophyllus Pennell |
| Penstemon lemhiensis (Keck) Keck & Cronq. |
| Penstemon lentus Pennell |
| Penstemon leonardii Rydb. |
| Penstemon leptanthus Pennell |
| Penstemon linarioides Gray |
| Penstemon longiflorus (Pennell) S.L.Clark |
| Penstemon lyallii (Gray) Gray |
| Penstemon marcusii (Keck) N. Holmgren |
| Penstemon mensarum Pennell |
| Penstemon mirus A.Nelson |
| Penstemon miser Gray |
| Penstemon moffatii Eastw. |
| Penstemon monoensis Heller |
| Penstemon montanus Greene |
| Penstemon moriahensis N.Holmgren |
| Penstemon multiflorus Chapman ex Benth. |
| Penstemon murcronatus N.Holmgr. |
| Penstemon murrayanus Hook. |
| Penstemon nanus Keck |
| Penstemon navajoa N.Holmgren |
| Penstemon neomexicanus Woot. & Standl. |
| Penstemon neotericus Keck |
| Penstemon newberryi Gray |
| Penstemon nitidus Dougl. ex Benth. |
| Penstemon nudiflorus Gray |
| Penstemon oklahomensis Pennell |
| Penstemon oliganthus Woot. & Standl. |
| Penstemon ophianthus Pennell |
| Penstemon osterhoutii Pennell |
| Penstemon ovatus Dougl. ex Hook. |
| Penstemon pachyphyllus Gray ex Rydb. |
| Penstemon pahutensis N. Holmgren |
| Penstemon pallidus Small |
| Penstemon palmeri Gray |
| Penstemon papillatus J.T.Howell |
| Penstemon parishii Gray (pro sp.) |
| Penstemon parryi (Gray) Gray |
| Penstemon parviflorus Pennell |
| Penstemon parvus Pennell |
| Penstemon patens (M.E.Jones) N. Holmgren |
| Penstemon payettensis A.Nels. & J.F.Macbr. |
| Penstemon paysoniorum Keck |
| Penstemon peckii Pennell |
| Penstemon peirsonii Munz & I.M.Johnston |
| Penstemon penlandii W.A.Weber |
| Penstemon pennellianus Keck |
| Penstemon perpulcher A.Nels. |
| Penstemon personatus Keck |
| Penstemon petiolatus Brandeg. |
| Penstemon pinifolius Greene |
| Penstemon pinorum L.& J.Shultz |
| Penstemon platyphyllus Rydb. |
| Penstemon pratensis Greene |
| Penstemon procerus Dougl. ex Graham |
| Penstemon pruinosus Dougl. ex Lindl. |
| Penstemon pseudoparvus Crosswhite |
| Penstemon pseudoputus (Crosswhite) N.Holmgren |
| Penstemon pseudospectabilis M.E.Jones |
| Penstemon pudicus Reveal & Beatley |
| Penstemon pumilus Nutt. |
| Penstemon purpusii Brandeg. |
| Penstemon putus A.Nels. |
| Penstemon radicosus A.Nels. |
| Penstemon ramosus Crosswhite |
| Penstemon rattanii Gray |
| Penstemon retrosus Payson Ex Pennell |
| Penstemon rhizomatosus N.Holmgren |
| Penstemon richardsonii Dougl. ex Lindl. |
| Penstemon roezlii Regel |
| Penstemon rostriflorus Kellogg |
| Penstemon rubicundus Keck |
| Penstemon rupicola (Piper) T.J.Howell |
| Penstemon rydbergii A.Nels. |
| Penstemon saxosorum Pennell |
| Penstemon scapoides Keck |
| Penstemon scariosus Pennell |
| Penstemon secundiflorus Benth. |
| Penstemon seorsus (A.Nels.) Keck |
| Penstemon sepalulus A.Nels. |
| Penstemon serrulatus Menzies ex Sm. |
| Penstemon smallii Heller Small's |
| Penstemon spatulatus Pennell |
| Penstemon speciosus Dougl. ex Lindl. |
| Penstemon spectabilis Thurb. ex Gray |
| Penstemon stenophyllus (Gray) T.J.Howell |
| Penstemon stephensii Brandeg. |
| Penstemon strictiformis Rydb. |
| Penstemon strictus Benth. |
| Penstemon subglaber Rydb. |
| Penstemon subserratus Pennell |
| Penstemon subulatus M.E.Jones |
| Penstemon sudans M.E.Jones |
| Penstemon superbus A.Nels. |
| Penstemon tenuiflorus Pennell |
| Penstemon tenuis Small |
| Penstemon teucrioides Greene |
| Penstemon thompsoniae (Gray) Rydb. |
| Penstemon thurberi Torr. |
| Penstemon tidestromii Pennell |
| Penstemon tiehmii N.Holmgren |
| Penstemon tracyi Keck |
| Penstemon triflorus Heller |
| Penstemon triphyllus Dougl. ex Lindl. |
| Penstemon tubiflorus Nutt. |
| Penstemon tusharensis N.Holmgren |
| Penstemon uintahensis Pennell |
| Penstemon unilateralis Rydb. |
| Penstemon utahensis Eastw. |
| Penstemon venustus Dougl. ex Lindl. |
| Penstemon virens Pennell ex Rydb. |
| Penstemon virgatus Gray |
| Penstemon wardii Gray |
| Penstemon washingtonensis Keck |
| Penstemon watsonii Gray |
| Penstemon whippleanus Gray |
| Penstemon wilcoxii Rydb. |
| Penstemon wrightii Hook. |
| Penstemon yampaensis Penl. |