| | |
| Penstemon acaulis yampaensis (Penland) Neese | Penstemon yampaensis Penland sect. Cristati |
| Penstemon acuminatus congestus M.E.Jones, Proc. Calif. Acad. Sci. ser. 2. 5: 714 (1895) | Penstemon pachyphyllus A.Gray ex Rydb. sect. Coerulei |
| Penstemon acuminatus fendleri (Torr. & A.Gray) M.E.Jones | Penstemon fendleri Torr. & A.Gray sect. Coerulei |
| Penstemon acuminatus fendleri M.E.Jones | Penstemon acuminatus Douglas ex Lindl. sect. Coerulei |
| Penstemon albifluvis England, Great Basin Naturalist 42(3): 367 (1982) | Penstemon scariosus Pennell sect. Glabri |
| Penstemon alpinus riparius (A.Nelson) Pennell | Penstemon glaber Pursh sect. Glabri |
| Penstemon ambiguus thurberi (Torr.) A.Gray | Penstemon thurberi Torr. sect. Ambigui |
| Penstemon amoenus Kunze | Penstemon venustus Douglas ex Lindl. sect. Saccanthera |
| Penstemon amplexicaulis Buckley | Penstemon buckleyi Pennell sect. Coerulei |
| Penstemon amplexicaulis Moench | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon angelicus (I.M.Johnst.) R.Moran | Penstemon clevelandii A.Gray sect. Spectabiles |
| Penstemon argutus Paxton | Penstemon serrulatus Menzies sect. Saccanthera |
| Penstemon arizonicus (A.Gray) A.Heller | Penstemon deaveri Crosswh. sect. Glabri |
| Penstemon arizonicus A.Heller | Penstemon whippleanus A.Gray sect. Penstemon |
| Penstemon arkansanus pubescens Pennell | Penstemon pallidus Small sect. Penstemon |
| Penstemon attenuatus varians A.Nelson | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon australis laxiflorus (Pennell) R.W.Benn. | Penstemon laxiflorus Pennell sect. Penstemon |
| Penstemon azureus ambiguus A.Gray | Penstemon sepalulus A.Nelson sect. Saccanthera |
| Penstemon bakeri Greene | Penstemon hallii A.Gray sect. Glabri |
| Penstemon brevisepalus heterolasius Fernald | Penstemon pallidus Small sect. Penstemon |
| Penstemon bridgesii A.Gray | Penstemon rostriflorus Kellogg sect. Bridgesiani |
| Penstemon caelestinus Pennell | Penstemon albertinus Greene sect. Penstemon |
| Penstemon caespitosus suffruticosus A.Gray | Penstemon xylus A.Nelson sect. Caespitosi |
| Penstemon caespitosus thompsoniae (A.Gray) A.Nelson | Penstemon thompsoniae (A.Gray) Rydb. sect. Caespitosi |
| Penstemon campanulatus roseus (G.Don) Voss. | Penstemon roseus (Cerv. ex Sweet) G.Don sect. Campanulati |
| Penstemon cephalanthus Pennell | Penstemon attenuatus Douglas sect. Penstemon |
| Penstemon cinerascens Greene | Penstemon roezlii Regel sect. Saccanthera |
| Penstemon cinereus Piper | Penstemon humilis Nutt. ex A.Gray sect. Penstemon |
| Penstemon clevelandii angelicus I.M.Johnst. | Penstemon clevelandii A.Gray sect. Spectabiles |
| Penstemon collinus A.Nelson | Penstemon humilis Nutt. ex A.Gray sect. Penstemon |
| Penstemon confertus attenuatus (Douglas) M.E.Jones | Penstemon attenuatus Douglas sect. Penstemon |
| Penstemon confertus attenuatus M.E.Jones | Penstemon confertus Douglas sect. Penstemon |
| Penstemon confertus geniculatus (Greene) Jeps. | Penstemon heterodoxus A.Gray sect. Penstemon |
| Penstemon confertus globosus Piper, Bull. Torrey Bot. Club 27: 397 (1900) | Penstemon globosus (Piper) Pennell & D.D.Keck sect. Penstemon |
| Penstemon confertus procerus (Douglas ex Graham) Coville | Penstemon procerus Douglas ex Graham sect. Penstemon |
| Penstemon confusus patens M.E.Jones, Contr. West. Bot. 12: 63 (1908) | Penstemon patens (M.E.Jones) N.H.Holmgren sect. Gentianoides |
| Penstemon confusus typicus D.D.Keck | Penstemon confusus M.E.Jones sect. Gentianoides |
| Penstemon congestus (M.E.Jones) Pennell | Penstemon pachyphyllus A.Gray ex Rydb. sect. Coerulei |
| Penstemon corymbosus Benth. ex A.DC. | Keckiella corymbosa (Benth. ex A,DC.) Straw |
| Penstemon crassifolius Lindl. | Penstemon fruticosus (Pursh) Greene sect. Erianthera |
| Penstemon cristatus Fraser | Penstemon eriantherus Nutt. ex Pursh sect. Cristati |
| Penstemon cyananthus compactus D.D.Keck, Amer. Midl. Naturalist 23: 615 (1940) | Penstemon compactus (D.D.Keck) Crosswh. sect. Glabri |
| Penstemon cyananthus longiflorus Pennell, Contr. U.S. Natl. Herb. 20(9): 353 (1920) | Penstemon longiflorus (Pennell) S.L.Clark sect. Glabri |
| Penstemon davidsonii ellipticus (J.M.Coulter & Fisher) B.Boivin | Penstemon ellipticus J.M.Coult. & Fisher sect. Erianthera |
| Penstemon decurvus Pennell ex Crosswh. | Penstemon humilis Nutt. ex A.Gray sect. Penstemon |
| Penstemon depressus Greene | Penstemon confertus Douglas sect. Penstemon |
| Penstemon deserticola Piper | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon desertipicti A.Nelson, Univ. Wyoming, Publ. Sci., Bot. 1: 130 (1926) | Penstemon caespitosus Nutt. ex A.Gray sect. Caespitosi |
| Penstemon desertorum M.E.Jones | Penstemon calcareus Brandegee sect. Cristati |
| Penstemon deustis savagei L.F.Hend. | Penstemon deustus Douglas ex Lindl. sect. Penstemon |
| Penstemon deustus arenarius (Greene) Jeps. | Penstemon arenarius Greene sect. Penstemon |
| Penstemon deustus sudans (M.E.Jones) Pennell & D.D.Keck | Penstemon sudans M.E.Jones sect. Penstemon |
| Penstemon diffusus Douglas | Penstemon serrulatus Menzies sect. Saccanthera |
| Penstemon digitalis attenuatus (Douglas) Trautv. | Penstemon attenuatus Douglas sect. Penstemon |
| Penstemon digitalis gracilis (Nutt.) Trautv. | Penstemon gracilis Nutt. sect. Penstemon |
| Penstemon digitalis pubescens (Aiton) Trautv. | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon divergens M.E.Jones | Penstemon monoensis A.Heller sect. Cristati |
| Penstemon dolius duchesnensis N.H.Holmgren, Brittonia 31: 219 (1979) | Penstemon duchesnensis.(N.H.Holmgren) Neese sect. Cristati |
| Penstemon eastwoodiae A.Heller | Penstemon utahensis Eastw. sect. Gentianoides |
| Penstemon erosus Rydb. | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon filifolius Nutt. ex Benth. | Penstemon laricifolius Hook. & Arn. sect. Cristati |
| Penstemon francisci-pennellii Crosswh. Leafl. W. Bot. 10: 170 (1965) | Penstemon leiophyllus Pennell sect. Glabri |
| Penstemon frutescens Lamb. | Pennellianthus frutescens (Lamb.) Crosswh. trib. Cheloneae |
| Penstemon fruticiformis incertus (Brandegee) Munz & I.M.Johnst. | Penstemon incertus Brandegee sect. Spectabiles |
| Penstemon fruticosus cardwellii (Howell) Piper | Penstemon cardwellii Howell sect. Erianthera |
| Penstemon frutiiciformis spiciformis Jeps. | Penstemon fruticiformis Coville sect. Spectabiles |
| Penstemon geniculatus Greene | Penstemon heterodoxus A.Gray sect. Penstemon |
| Penstemon glaber cyananthus (Hook.) A.Gray | Penstemon cyananthus Hook. sect. Glabri |
| Penstemon glaber fremontii (Torr. & A.Gray) M.E.Jones | Penstemon fremontii Torr. & A.Gray sect. Glabri |
| Penstemon glaber occidentalis A.Gray | Penstemon glaber Pursh sect. Glabri |
| Penstemon glaber speciosus (Douglas ex Lindl.) Regel | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon glaber utahensis S.Watson | Penstemon subglaber Rydb. sect. Glabri |
| Penstemon glaber wardii (A.Gray) M.E.Jones | Penstemon wardii A.Gray sect. Glabri |
| Penstemon glastifolius Greene | Penstemon heterodoxus A.Gray sect. Penstemon |
| Penstemon glaucifolius A.Gray | Penstemon azureus Benth. sect. Saccanthera |
| Penstemon glaucus Graham | Penstemon gracilis Nutt. sect. Penstemon |
| Penstemon glaucus stenosepalus A.Gray | Penstemon whippleanus A.Gray sect. Penstemon |
| Penstemon gordonianus A.Gray | Penstemon glaber Pursh sect. Glabri |
| Penstemon gordonii Hook. | Penstemon glaber Pursh sect. Glabri |
| Penstemon gracilentus ursorum Jeps. | Penstemon gracilentus A.Gray sect. Saccanthera |
| Penstemon gracilis wisconsinensis (Pennell) Fassett | Penstemon gracilis Nutt. sect. Penstemon |
| Penstemon grandiflorus Nutt. | Penstemon bradburyi Pursh sect. Coerulei |
| Penstemon grinnellii scrophularioides (M.E.Jones) Munz | Penstemon grinnellii Eastw. sect. Spectabiles |
| Penstemon guadalupensis ernestii Pennell | Penstemon guadalupensis A.Heller sect. Cristati |
| Penstemon hallii arizonicus A.Gray | Penstemon deaveri Crosswh. sect. Glabri |
| Penstemon hansoni A.Nelson | Penstemon cobaea Nutt. sect. Cristati |
| Penstemon helleri Small | Penstemon triflorus A.Heller sect. Cristati |
| Penstemon heterophyllus azureus (Benth.) Jeps. | Penstemon azureus Benth. sect. Saccanthera |
| Penstemon heterophyllus latifolius S.Watson | Penstemon platyphyllus Rydb. sect. Saccanthera |
| Penstemon heterophyllus S.Watson | Penstemon sepalulus A.Nelson sect. Saccanthera |
| Penstemon hians (Piper) I.M.Johnst. | Penstemon gairdneri Hook. sect. Penstemon |
| Penstemon hirsutus albiflorus Farw. | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon humilis desereticus S.L.Welsh | Penstemon humilis Nutt. ex A.Gray sect. Penstemon |
| Penstemon incanus (A.Gray) Tidestr, | Penstemon pumilus Nutt. sect. Cristati |
| Penstemon intonsus A.Heller | Keckiella corymbosa (Benth. ex A,DC.) Straw |
| Penstemon jaffrayanus Hook. | Penstemon azureus Benth. sect. Saccanthera |
| Penstemon jamesii breviculus D.D.Keck, Bull. Torrey Bot. Club 65: 241 (1938) | Penstemon breviculus (D.D.Keck) G.T.Nisbet & R.C.Jacks. sect. Cristati |
| Penstemon jamesii ophianthus (Pennell) D.D.Keck | Penstemon ophianthus Pennell sect. Cristati |
| Penstemon jamesii typicus D.D.Keck | Penstemon jamesii Benth. sect. Cristati |
| Penstemon keckii Clokey, Madrońo 4: 128 (1937) | Penstemon leiophyllus Pennell sect. Glabri |
| Penstemon kennedyi A.Nelson | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon kingii glaucus Kellogg | Penstemon kingii S.Watson sect. Saccanthera |
| Penstemon kunthii G.Don | Penstemon roseus (Cerv. ex Sweet) G.Don sect. Campanulati |
| Penstemon lacerellus Greene | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon laetus albus P.C.Everett | Penstemon laetus A.Gray sect. Saccanthera |
| Penstemon laetus filiformis D.D.Keck, Univ. Calif. Publ. Bot. 16: 394 (1932) | Penstemon filiformis (D.D.Keck) D.D.Keck sect. Saccanthera |
| Penstemon laetus roezlii (Regel) D.D.Keck | Penstemon roezlii Regel sect. Saccanthera |
| Penstemon lassenianus Greene | Penstemon confertus Douglas sect. Penstemon |
| Penstemon latifolius Hoffmanns. | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon latiusculus Greene | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon leptanthus Pennell | Penstemon tidestromii Pennell sect. Glabri |
| Penstemon leucanthus Greene | Penstemon heterophyllus Lindl. sect. Saccanthera |
| Penstemon lewisii Benth. | Penstemon fruticosus (Pursh) Greene sect. Erianthera |
| Penstemon linarioides californicus Munz & I. M. Johnst., Bull. S. Calif. Acad. Sci. 23: 31 (1924) | Penstemon californicus (Munz & I.M.Johnst.) D.D.Keck sect. Caespitosi |
| Penstemon linarioides compactifolius D.D.Keck | Penstemon linarioides A.Gray sect. Caespitosi |
| Penstemon linarioides seorsus A.Nelson, Bot. Gaz. 54: 147 (1912) | Penstemon seorsus (A.Nelson) D.D.Keck sect. Penstemon |
| Penstemon linearifolius J.M.Coult. & Fisher | Penstemon lyallii (A.Gray) A.Gray sect. Erianthera |
| Penstemon lineolatus Greene | Penstemon radicosus A.Nelson sect. Penstemon |
| Penstemon longifolius Scheele | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon lyallii linearifolius (J.M.Coult. & Fisher) Krautter | Penstemon lyallii (A.Gray) A.Gray sect. Erianthera |
| Penstemon macbridei A.Nelson | Penstemon cusickii A.Gray sect. Saccanthera |
| Penstemon mackayanus Knowles & Westc. | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon macranthus Eastw., Bull. Torrey Bot. Club 32: 207 (1905) | Penstemon palmeri A.Gray sect. Spectabiles |
| Penstemon maguirei Crosswh. | Penstemon arenarius Greene sect. Penstemon |
| Penstemon menziesii davidsonii (Greene) G.N.Jones | Penstemon davidsonii Greene sect. Erianthera |
| Penstemon menziesii lyallii A.Gray, Proc. Amer. Acad. Arts 6: 76 (1862) | Penstemon lyallii (A.Gray) A.Gray sect. Erianthera |
| Penstemon meziesii newberryi (A.Gray) A.Gray | Penstemon newberryi A.Gray sect. Erianthera |
| Penstemon micranthus Nutt. | Penstemon procerus Douglas ex Graham sect. Penstemon |
| Penstemon micranthus Torr. | Penstemon strictus Benth. sect. Glabri |
| Penstemon minidokanus A.Nelson & J.F.Macbr. | Penstemon perpulcher A.Nelson sect. Glabri |
| Penstemon minor (A.Gray) D.D.Keck | Penstemon anguineus Eastw. sect. Penstemon |
| Penstemon moffatii marcusii D.D.Keck, Bull. Torrey Bot. Club 65: 243 (1938) | Penstemon marcusii (D.D.Keck) N.H.Holmgren sect. Cristati |
| Penstemon moffatii paysonii (Pennell) D.D.Keck | Penstemon moffattii Eastw. sect. Cristati |
| Penstemon multicaulis Pennell | Penstemon arkansanus Pennell sect. Penstemon |
| Penstemon nelsoniae D.D.Keck & Thomps. | Penstemon attenuatus Douglas sect. Penstemon |
| Penstemon newberryi rupicola Piper, Bull. Torrey Bot. Club 27: 397 (1900) | Penstemon rupicola (Piper) Howell sect. Erianthera |
| Penstemon nitidus major Benth. | Penstemon nitidus Douglas ex Benth. sect. Coerulei |
| Penstemon nyeensis Crosswh. | Penstemon kingii S.Watson sect. Saccanthera |
| Penstemon oreganus (A.Gray) Howell | Penstemon gairdneri Hook. sect. Penstemon |
| Penstemon ovatus pinetorum (Piper) Piper | Penstemon wilcoxii Rydb. sect. Penstemon |
| Penstemon pachyphyllus mucronatus (N.H.Holmgren) Neese | Penstemon mucronatus N.H.Holmgren sect. Coerulei |
| Penstemon pallescens Osterh. | Penstemon whippleanus A.Gray sect. Penstemon |
| Penstemon pallidus arkansanus (Pennell) R.W.Benn. | Penstemon arkansanus Pennell sect. Penstemon |
| Penstemon palmeri grinnellii (Eastw.) Munz & I.M.Johnst. | Penstemon grinnellii Eastw. sect. Spectabiles |
| Penstemon pandus (A.Nelson & J.F.Macbr.) A.Nelson & J.F.Macb | Penstemon perpulcher A.Nelson sect. Glabri |
| Penstemon parviflorus Pennell | Penstemon auriberbis Pennell sect. Cristati |
| Penstemon paysonii Pennell | Penstemon moffattii Eastw. sect. Cristati |
| Penstemon perpulcher pandus A.Nelson & J.F.Macbr. | Penstemon perpulcher A.Nelson sect. Glabri |
| Penstemon phlogifolius Greene | Penstemon watsonii A.Gray sect. Penstemon |
| Penstemon pilifer A.Heller | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon pilosigulatus A.Nelson | Penstemon ophianthus Pennell sect. Cristati |
| Penstemon pinetorum (Piper) Piper | Penstemon wilcoxii Rydb. sect. Penstemon |
| Penstemon pringlei S.Watson | Penstemon dasyphyllus A.Gray sect. Chamaeleon |
| Penstemon procerus geniculatus (Greene) Smiley | Penstemon heterodoxus A.Gray sect. Penstemon |
| Penstemon productus Greene | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon pseudohumilis M.E.Jones | Penstemon marcusii (D.D.Keck) N.H.Holmgren sect. Cristati |
| Penstemon pseudospectabilis clutei (A.Nelson) D.D.Keck | Penstemon clutei A.Nelson sect. Spectabiles |
| Penstemon puberulentus Rydb. | Penstemon gairdneri Hook. sect. Penstemon |
| Penstemon puberulus M.E.Jones | Penstemon humilis Nutt. ex A.Gray sect. Penstemon |
| Penstemon puberulus Wooton & Standl. | Penstemon metcalfei Wooton & Standl. sect. Penstemon |
| Penstemon pubescens Aiton | Penstemon hirsutus (L.) Willd. sect. Penstemon |
| Penstemon pubescens gracilis (Nutt. ) A.Gray | Penstemon gracilis Nutt. sect. Penstemon |
| Penstemon pumilus incanus A.Gray | Penstemon pumilus Nutt. sect. Cristati |
| Penstemon pumilus thompsoniae A.Gray, Syn. Fl. N. Amer. 2(1): 269 (1878) | Penstemon thompsoniae (A.Gray) Rydb. sect. Caespitosi |
| Penstemon puniceus A.Gray | Penstemon superbus A.Nelson sect. Gentianoides |
| Penstemon puniceus parryi A.Gray, Rep. U.S. Mex. Bound., Bot. [Emory] 2(1): 113 (1859) | Penstemon parryi (A.Gray) A.Gray sect. Gentianoides |
| Penstemon rattanii minor A.Gray | Penstemon anguineus Eastw. sect. Penstemon |
| Penstemon rex A.Nelson & J.F.Macbr. | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon riparius A.Nelson | Penstemon glaber Pursh sect. Glabri |
| Penstemon roezlii violaceus Brandegee | Penstemon roezlii Regel sect. Saccanthera |
| Penstemon rothrockii A.Gray | Keckiella rothrockii (A.Gray) Straw trib. Cheloneae |
| Penstemon rydbergii varians (A.Nelson) Cronquist | Penstemon rydbergii A.Nelson sect. Penstemon |
| Penstemon saliens Rydb. | Penstemon eriantherus Nutt. ex Pursh sect. Cristati |
| Penstemon scabridus Eastw. | Keckiella rothrockii (A.Gray) Straw trib. Cheloneae |
| Penstemon scoparius A.Nelson | Penstemon thurberi Torr. sect. Ambigui |
| Penstemon scrophularioides M.E.Jones | Penstemon grinnellii Eastw. sect. Spectabiles |
| Penstemon secundiflorus caudatus A.Nelson | Penstemon secundiflorus Benth. sect. Coerulei |
| Penstemon shantzii A.Nelson | Penstemon parryi (A.Gray) A.Gray sect. Gentianoides |
| Penstemon shockleyi S.Watson | Keckiella rothrockii (A.Gray) Straw trib. Cheloneae |
| Penstemon similis A.Nelson | Penstemon jamesii Benth. sect. Cristati |
| Penstemon speciosus kennedyi (A.Nelson) D.D.Keck | Penstemon speciosus Douglas ex Lindl. sect. Glabri |
| Penstemon speciosus lemhiensis D.D.Keck, Amer. Midl. Naturalist 23: 612 (1940) | Penstemon lemhiensis (D.D.Keck) D.D.Keck & Cronquist sect. Glabri |
| Penstemon spinulosus Wooton & Standl. | Penstemon heterophyllus Lindl. sect. Saccanthera |
| Penstemon stenophyllus dasyphyllus (A.Gray) A.Gray | Penstemon dasyphyllus A.Gray sect. Chamaeleon |
| Penstemon stenosepalus (A.Gray) Howell | Penstemon whippleanus A.Gray sect. Penstemon |
| Penstemon strictus angustus Pennell | Penstemon strictus Benth. sect. Glabri |
| Penstemon strictus strictiformis (Rydb.) D.D.Keck | Penstemon strictiformis Rydb. sect. Glabri |
| Penstemon suffrutescens Rydb. | Penstemon crandallii A.Nelson sect. Caespitosi |
| Penstemon suffruticosus Douglas ex Benth. | Penstemon venustus Douglas ex Lindl. sect. Saccanthera |
| Penstemon tenellus Kellogg | Penstemon azureus Benth. sect. Saccanthera |
| Penstemon teretifolius Fraser ex Nutt. | Penstemon albidus Nutt. sect. Cristati |
| Penstemon thompsoniae desperatus Neese | Penstemon thompsoniae (A.Gray) Rydb. sect. Caespitosi |
| Penstemon tinctus Pennell | Penstemon procerus Douglas ex Graham sect. Penstemon |
| Penstemon triphyllus diphyllus (Rydb.) D.D.Keck | Penstemon diphyllus Rydb. sect. Saccanthera |
| Penstemon truncatus Pennell | Penstemon cinicola D.D.Keck sect. Penstemon |
| Penstemon tusharensis N.H.Holmgr. | Penstemon xylus A.Nelson sect. Caespitosi |
| Penstemon tweedyi Canby & Rose | Chionophila tweedyi (Canby & Rose) L.F.Hend. trib. Cheloneae |
| Penstemon unilateralis Rydb. | Penstemon secundiflorus Benth. sect. Coerulei |
| Penstemon utahensis (S.Watson) A.Nelson | Penstemon subglaber Rydb. sect. Glabri |
| Penstemon veronicifolius Greene | Penstemon attenuatus Douglas sect. Penstemon |
| Penstemon violaceus (Brandegee) A.Nelson | Penstemon roezlii Regel sect. Saccanthera |
| Penstemon virgatus arizonicus (A.Gray) D.D.Keck | Penstemon deaveri Crosswh. sect. Glabri |
| Penstemon virgatus pseudoputus Crosswh., Amer. Midl. Naturalist 77: 35 (1967) | Penstemon pseudoputus (Crosswh.) N.H.Holmgren sect. Glabri |
| Penstemon virgatus putus (A.Nelson) Crosswh. | Penstemon putus A.Nelson sect. Glabri |
| Penstemon viscidulus Nees | Penstemon albidus Nutt. sect. Cristati |
| Penstemon washoensis Greene | Penstemon confertus Douglas sect. Penstemon |
| Penstemon watsonii laxus (A.Nelson) D.D.Keck | Penstemon laxus A.Nelson sect. Penstemon |
| Penstemon watsonii typicus D.D.Keck | Penstemon watsonii A.Gray sect. Penstemon |
| Penstemon wherryi Pennell | Penstemon arkansanus Pennell sect. Penstemon |
| Penstemon wisconsinensis Pennell | Penstemon gracilis Nutt. sect. Penstemon |
| Penstemon woodsii A.Nelson | Penstemon montanus Greene sect. Erianthera |