The ITIS Logo The Search Results banner for the ITIS Data pages
Results of: Search in every Kingdom for Scientific Name containing 'Penstemon'
 
 Kingdom Animalia
  Dibolia penstemonis Parry, 1974 – valid
  Phytomyza penstemonella Spencer, 1981 – valid
  Phytomyza penstemonis Spencer, 1969 – valid
 
 Kingdom Plantae
  Aliciella penstemonoides (M.E. Jones) J.M. Porter – accepted – Black Canyon gilia
  Gilia penstemonoides M.E. Jones – not accepted – Black Canyon gilia
  Penstemon Schmidel – accepted – penstémons, beardtongue
  Penstemon abietinus Pennell – accepted – firleaf beardtongue
  Penstemon absarokensis Evert – accepted – Absaroka Range beardtongue, Absaroka beardtongue
  Penstemon acaulis L.O. Williams – accepted – stemless beardtongue
  Penstemon acaulis var. yampaensis (Penland) Neese – not accepted
  Penstemon acuminatus Douglas ex Lindl. – accepted – sharpleaf penstemon, sand-dune beardtongue
  Penstemon acuminatus var. acuminatus Douglas ex Lindl. – accepted – sharpleaf penstemon
  Penstemon acuminatus var. latebracteatus N.H. Holmgren – accepted – sharpleaf penstemon
  Penstemon aggregatus Pennell – not accepted
  Penstemon alamosensis Pennell & G.T. Nisbet – accepted – Los Alamos beardtongue, Alamo beardtongue
  Penstemon albertinus Greene – accepted – Alberta beardtongue
  Penstemon albidus Nutt. – accepted – white penstemon
  Penstemon albifluvis England – not accepted
  Penstemon albomarginalis M.E. Jones – not accepted
  Penstemon albomarginatus M.E. Jones – accepted – whitemargin beardtongue, white margin penstemon, whitemargin penstemon, white-margined penstemon
  Penstemon alluviorum Pennell – not accepted – lowland beardtongue
  Penstemon alpinus Torr. – not accepted
  Penstemon alpinus ssp. brandegeei (Porter) Penland – not accepted
  Penstemon alpinus ssp. magnus (Pennell) Penland – not accepted
  Penstemon alpinus var. alpinus Torr. – not accepted
  Penstemon alpinus var. nagnus (Pennell) Penland – not accepted
  Penstemon ambiguus Torr. – accepted – gilia penstemon, bush penstemon, gilia beardtongue
  Penstemon ambiguus ssp. laevissimus D.D. Keck – not accepted
  Penstemon ambiguus var. ambiguus Torr. – accepted – gilia penstemon, gilia beardtongue
  Penstemon ambiguus var. laevissimus (D.D. Keck) N.H. Holmgren – accepted – pink plains beardtongue, gilia penstemon, pink plains penstemon
  Penstemon ammophilum N.H. Holmgren & L.M. Shultz – not accepted
  Penstemon ammophilus N.H. Holmgren & L.M. Shultz – accepted – sandloving penstemon
  Penstemon anguineus Eastw. – accepted – Siskiyou beardtongue
  Penstemon angustifolius Nutt. ex Pursh – accepted – broadbeard beardtongue, broad-beard beardtongue, narrowleaf penstemon
  Penstemon angustifolius ssp. caudatus (A. Heller) D.D. Keck – not accepted
  Penstemon angustifolius ssp. venosus D.D. Keck – not accepted
  Penstemon angustifolius var. angustifolius Nutt. ex Pursh – accepted – broadbeard beardtongue, broad-beard beardtongue
  Penstemon angustifolius var. caudatus (A. Heller) Rydb. – accepted – broadbeard beardtongue
  Penstemon angustifolius var. dulcis Neese – accepted – broadbeard beardtongue
  Penstemon angustifolius var. venosus (D.D. Keck) N.H. Holmgren – accepted – broadbeard beardtongue, broadbeard penstemon
  Penstemon angustifolius var. vernalensis N.H. Holmgren – accepted – broadbeard beardtongue
  Penstemon antirrhinoides Benth. – not accepted
  Penstemon antirrhinoides ssp. microphyllus (A. Gray) D.D. Keck – not accepted
  Penstemon arenarius Greene – accepted – sanddune penstemon, Nevada sanddune beardtongue
  Penstemon arenicola A. Nelson – accepted – sand penstemon
  Penstemon aridus Rydb. – accepted – stiffleaf penstemon
  Penstemon arkansanus Pennell – accepted – Arkansas beardtongue
  Penstemon arkansanus var. pubescens Pennell – not accepted
  Penstemon assurgens D.D. Keck – not accepted
  Penstemon attenuatus Douglas ex Lindl. – accepted – sulphur penstemon
  Penstemon attenuatus ssp. militaris (Greene) D.D. Keck – not accepted
  Penstemon attenuatus ssp. palustris (Pennell) D.D. Keck – not accepted
  Penstemon attenuatus ssp. pseudoprocerus (Rydb.) D.D. Keck – not accepted
  Penstemon attenuatus var. attenuatus Douglas ex Lindl. – accepted – sulphur penstemon
  Penstemon attenuatus var. militaris (Greene) Cronquist – accepted – South Idaho penstemon
  Penstemon attenuatus var. palustris (Pennell) Cronquist – accepted – sulphur beardtongue
  Penstemon attenuatus var. pseudoprocerus (Rydb.) Cronquist – accepted – small penstemon
  Penstemon atwoodii S.L. Welsh – accepted – Kaiparowits beardtongue
  Penstemon auriberbis Pennell – accepted – Colorado beardtongue
  Penstemon australis Small – accepted – Eustis Lake beardtongue
  Penstemon australis ssp. australis Small – not accepted – Eustis Lake beardtongue
  Penstemon australis ssp. laxiflorus (Pennell) R.W. Benn. – not accepted – Eustis Lake beardtongue
  Penstemon australis var. ameles Crosswh. – not accepted
  Penstemon azureus Benth. – accepted – azure penstemon
  Penstemon azureus ssp. angustissimus (A. Gray) D.D. Keck – not accepted – azure penstemon
  Penstemon azureus ssp. azureus Benth. – not accepted – azure penstemon
  Penstemon azureus var. angustissimus A. Gray – accepted – azure penstemon
  Penstemon azureus var. azureus Benth. – accepted – beardtongue
  Penstemon azureus var. parvulus A. Gray – not accepted – azure penstemon
  Penstemon baccharifolius Hook. – accepted – baccharisleaf beardtongue
  Penstemon barbatus (Cav.) Roth – accepted – beardlip penstemon
  Penstemon barbatus ssp. barbatus (Cav.) Roth – not accepted – beardlip penstemon
  Penstemon barbatus ssp. torreyi (Benth.) D.D. Keck – not accepted – Torrey's penstemon
  Penstemon barbatus ssp. trichander (A. Gray) D.D. Keck – not accepted – beardlip penstemon
  Penstemon barbatus var. barbatus (Cav.) Roth – accepted – beardlip penstemon
  Penstemon barbatus var. puberulus A. Gray – not accepted
  Penstemon barbatus var. torreyi (Benth.) A. Gray – accepted – beardlip penstemon
  Penstemon barbatus var. trichander A. Gray – accepted – Torrey's penstemon
  Penstemon barbatus var. trichanderi (A. Gray) D.D. Keck – not accepted
  Penstemon barnebyi N.H. Holmgren – accepted – Barneby's penstemon, White River Valley beardtongue
  Penstemon barrettiae A. Gray – accepted – Barrett's beardtongue
  Penstemon bicolor (Brandegee) Clokey & D.D. Keck – accepted – pinto beardtongue, pinto penstemon
  Penstemon bicolor ssp. bicolor (Brandegee) Clokey & D.D. Keck – not accepted – twocolor penstemon, pinto beardtongue
  Penstemon bicolor ssp. roseus Clokey & D.D. Keck – not accepted – pinto beardtongue, pinto penstemon, rosey pinto penstemon
  Penstemon bracteatus D.D. Keck – accepted – Red Canyon beardtongue
  Penstemon bradburii Pursh – not accepted
  Penstemon brandegeei (Porter) Rydb. – not accepted
  Penstemon brevibarbatus Crosswh. – not accepted
  Penstemon breviculus (D.D. Keck) G.T. Nisbet & R.C. Jacks. – accepted – shortstem penstemon, shortstem beardtongue
  Penstemon breviflorus Lindl. – not accepted
  Penstemon breviflorus ssp. glabrisepalus D.D. Keck – not accepted
  Penstemon brevisepalus Pennell – accepted
  Penstemon bridgesii A. Gray – not accepted
  Penstemon bridgesii var. amplexicaulis Monnet – not accepted
  Penstemon brittoniorum Pennell – not accepted
  Penstemon bryantiae D.D. Keck – not accepted
  Penstemon buckleyi Pennell – accepted – Buckley's penstemon, Buckley's beardtongue
  Penstemon caesius A. Gray – accepted – San Bernardino beardtongue
  Penstemon caespitosus Nutt. ex A. Gray – accepted – mat penstemon
  Penstemon caespitosus ssp. desertipicti (A. Nelson) D.D. Keck – not accepted
  Penstemon caespitosus ssp. perbrevis Pennell – not accepted
  Penstemon caespitosus var. caespitosus Nutt. ex A. Gray – accepted – mat penstemon
  Penstemon caespitosus var. desertipicti (A. Nelson) N.H. Holmgren – accepted – mat penstemon, tufted penstemon
  Penstemon caespitosus var. perbrevis (Pennell) N.H. Holmgren – accepted – mat penstemon
  Penstemon caespitosus var. suffruticosus A. Gray – not accepted
  Penstemon calcareus Brandegee – accepted – limestone beardtongue, limestone penstemon
  Penstemon californicus (Munz & I.M. Johnst.) D.D. Keck – accepted – California penstemon
  Penstemon calycosus Small – accepted – longsepal beardtongue
  Penstemon campanulatus (Cav.) Willd. – accepted – bellflower beardtongue
  Penstemon campanulatus f. pulchellus (Lindl.) Voss – not accepted
  Penstemon campanulatus ssp. chihuahuensis Straw – not accepted
  Penstemon campanulatus var. chihuahuensis (Straw) B.L. Turner – accepted
  Penstemon canescens (Britton) Britton – accepted – eastern gray beardtongue
  Penstemon canescens var. brittoniorum (Pennell) Pennell – not accepted
  Penstemon canescens var. typicus Pennell – not accepted
  Penstemon cardinalis Wooton & Standl. – accepted – cardinal beardtongue
  Penstemon cardinalis ssp. cardinalis Wooton & Standl. – accepted – cardinal beardtongue
  Penstemon cardinalis ssp. regalis (A. Nelson) G.T. Nisbet & R.C. Jacks. – accepted – cardinal beardtongue
  Penstemon cardwellii Howell – accepted – Cardwell's beardtongue
  Penstemon carnosus Pennell – accepted – fleshy beardtongue
  Penstemon caryi Pennell – accepted – Cary's beardtongue, Cary beardtongue
  Penstemon caudatus A. Heller – not accepted
  Penstemon centranthifolius (Benth.) Benth. – accepted – scarlet bugler
  Penstemon cinerascens Greene ex C.F. Baker – not accepted
  Penstemon cinereus Piper – not accepted
  Penstemon cinereus ssp. foliatus D.D. Keck – not accepted
  Penstemon cinereus var. foliatus D.D. Keck – not accepted
  Penstemon cinicola D.D. Keck – accepted – ash penstemon
  Penstemon cleavelandii A. Gray – not accepted
  Penstemon cleavelandii var. cleavelandii A. Gray – not accepted
  Penstemon cleavelandii var. connatus (Munz & I.M. Johnst.) D.D. Keck – not accepted
  Penstemon cleavelandii var. mohavensis D.D. Keck – not accepted
  Penstemon cleburnei M.E. Jones – not accepted
  Penstemon clevelandii A. Gray – accepted – Cleveland's beardtongue
  Penstemon clevelandii ssp. clevelandii A. Gray – not accepted – Cleveland's beardtongue
  Penstemon clevelandii ssp. connatus (Munz & I.M. Johnst.) D.D. Keck – not accepted – San Jacinto beardtongue
  Penstemon clevelandii ssp. mohavensis D.D. Keck – not accepted – Cleveland's beardtongue
  Penstemon clevelandii var. clevelandii A. Gray – accepted – Cleveland's beardtongue
  Penstemon clevelandii var. connatus Munz & I.M. Johnst. – accepted
  Penstemon clevelandii var. mohavensis (D.D. Keck) McMinn – accepted – Cleveland's beardtongue
  Penstemon clutei A. Nelson – accepted – Sunset Crater beardtongue, Sunset Crater penstemon
  Penstemon cobaea Nutt. – accepted – cobaea beardtongue, cobaea penstemon
  Penstemon cobaea ssp. purpureus (Pennell) Pennell – not accepted
  Penstemon cobaea ssp. typicus Pennell – not accepted
  Penstemon cobaea var. cobaea Nutt. – accepted – cobaea beardtongue
  Penstemon cobaea var. purpureus Pennell – accepted – cobaea beardtongue
  Penstemon coloradoensis A. Nelson – not accepted
  Penstemon comarrhenus A. Gray – accepted – dusty penstemon, dusty beardtongue
  Penstemon compactus (D.D. Keck) Crosswh. – accepted – compact penstemon, cache beardtongue
  Penstemon concinnus D.D. Keck – accepted – Tunnel Springs beardtongue, Tunnel Springs penstemon
  Penstemon confertus Douglas ex Lindl. – accepted – yellow penstemon
  Penstemon confertus ssp. procerus (Douglas ex Graham) D.V. Clark – not accepted
  Penstemon confertus var. procerus (Douglas ex Graham) Coville – not accepted
  Penstemon confusus M.E. Jones – accepted – Owens Valley penstemon, Owens Valley beardtongue
  Penstemon confusus ssp. patens (M.E. Jones) D.D. Keck – not accepted
  Penstemon congestus (M.E. Jones) Pennell – not accepted
  Penstemon cordifolius Benth. – not accepted
  Penstemon corymbosus Benth. – not accepted
  Penstemon crandallii A. Nelson – accepted – Crandall's beardtongue
  Penstemon crandallii ssp. atratus D.D. Keck – accepted – Crandall's beardtongue
  Penstemon crandallii ssp. crandallii A. Nelson – accepted – Crandall's beardtongue
  Penstemon crandallii ssp. glabrescens (Pennell) D.D. Keck – accepted – Crandall's beardtongue
  Penstemon crandallii ssp. glabrescens var. glabrescens (Pennell) D.D. Keck – not accepted – Crandall's beardtongue
  Penstemon crandallii ssp. glabrescens var. taosensis (D.D. Keck) G.T. Nisbet & R.C. Jacks. – not accepted – Crandall's beardtongue
  Penstemon crandallii ssp. procumbens (Greene) D.D. Keck – accepted – Crandall's beardtongue
  Penstemon crandallii ssp. taosensis (D.D. Keck) Kartesz & Gandhi – not accepted – Taos penstemon
  Penstemon crandallii var. atractus (D.D. Keck) N.H. Holmgren – not accepted
  Penstemon crandallii var. atratus (D.D. Keck) N.H. Holmgren – not accepted
  Penstemon crandallii var. taosensis (D.D. Keck) G.T. Nisbet & R.C. Jacks. – not accepted
  Penstemon cusickii A. Gray – accepted – Cusick's beardtongue
  Penstemon cyananthus Hook. – accepted – Wasatch beardtongue
  Penstemon cyananthus ssp. compactus D.D. Keck – not accepted
  Penstemon cyananthus ssp. longiflorus Pennell – not accepted
  Penstemon cyananthus ssp. subglaber (A. Gray) Pennell – not accepted
  Penstemon cyananthus var. compactus (D.D. Keck) Neese – not accepted
  Penstemon cyananthus var. cyananthus Hook. – accepted – Wasatch beardtongue
  Penstemon cyananthus var. judyae N.D. Atwood – accepted – Wasatch beardtongue
  Penstemon cyananthus var. longiflorus (Pennell) Neese – not accepted
  Penstemon cyananthus var. subglaber (A. Gray) N.H. Holmgren – accepted – Wasatch beardtongue
  Penstemon cyaneus Pennell – accepted – blue penstemon
  Penstemon cyanocaulis Payson – accepted – bluestem beardtongue
  Penstemon cyathophorus Rydb. – accepted – Northpark penstemon, sagebrush beardtongue
  Penstemon dasyphyllus A. Gray – accepted – purple penstemon, Cochise beardtongue
  Penstemon davidsonii Greene – accepted – timberline penstemon, Davidson's penstemon
  Penstemon davidsonii ssp. menziesii D.D. Keck – not accepted
  Penstemon davidsonii var. davidsonii Greene – accepted – Davidson's penstemon
  Penstemon davidsonii var. ellipticus (J.M. Coult. & Fisher) B. Boivin – not accepted
  Penstemon davidsonii var. menziesii (D.D. Keck) Cronquist – accepted – Menzies' penstemon
  Penstemon davidsonii var. praeteritus Cronquist – accepted – timberline beardtongue, timberline penstemon
  Penstemon deamii Pennell – accepted – Deam's beardtongue
  Penstemon deaveri Crosswh. – accepted – Mt. Graham beardtongue
  Penstemon debilis O'Kane & J.L. Anderson – accepted – parachute beardtongue
  Penstemon decurvus Pennell ex Crosswh. – not accepted
  Penstemon degeneri Crosswh. – accepted – Degener's beardtongue, Degener beardtongue
  Penstemon deustus Douglas ex Lindl. – accepted – scabland penstemon
  Penstemon deustus ssp. heterander (Torr. & A. Gray) Pennell & D.D. Keck – not accepted
  Penstemon deustus ssp. sudans (M.E. Jones) Pennell & D.D. Keck – not accepted
  Penstemon deustus ssp. variabilis (Suksd.) Pennell & D.D. Keck – not accepted
  Penstemon deustus var. deustus Douglas ex Lindl. – accepted – hotrock penstemon, scabland penstemon
  Penstemon deustus var. heterander (Torr. & A. Gray) Cronquist – not accepted
  Penstemon deustus var. pedicellatus M.E. Jones – accepted – scabland penstemon, hotrock penstemon
  Penstemon deustus var. suffrutescens L.F. Hend. – accepted – scabland penstemon
  Penstemon deustus var. variabilis (Suksd.) Cronquist – accepted – scabland penstemon
  Penstemon digitalis Nutt. ex Sims – accepted – talus slope penstemon
  Penstemon diphyllus Rydb. – accepted – twoleaf beardtongue
  Penstemon discolor D.D. Keck – accepted – Catalina beardtongue
  Penstemon dissectus Elliott – accepted – dissected beardtongue
  Penstemon distans N.H. Holmgren – accepted – Mount Trumbull beardtongue
  Penstemon dolius M.E. Jones ex Pennell – accepted – Jone's penstemon, Jones' beardtongue
  Penstemon dolius var. dolius M.E. Jones ex Pennell – not accepted – Jones' beardtongue, Jones' penstemon
  Penstemon dolius var. duchesnensis N.H. Holmgren – not accepted – Duchesne penstemon
  Penstemon duchesnensis (N.H. Holmgren) Neese – accepted – Duchesne penstemon
  Penstemon eatonii A. Gray – accepted – Eaton's penstemon, firecracker penstemon
  Penstemon eatonii ssp. eatonii A. Gray – accepted – Eaton's penstemon, firecracker penstemon
  Penstemon eatonii ssp. exsertus (A. Nelson) D.D. Keck – accepted – firecracker penstemon, Eaton's penstemon, Eaton's firecracker
  Penstemon eatonii ssp. undosus (M.E. Jones) D.D. Keck – accepted – Eaton's penstemon, firecracker penstemon
  Penstemon eatonii var. eatonii A. Gray – not accepted – beardtongue
  Penstemon eatonii var. undosus M.E. Jones – not accepted
  Penstemon elegantulus Pennell – accepted – rockvine penstemon
  Penstemon ellipticus J.M. Coult. & Fisher – accepted – rocky ledge penstemon
  Penstemon eriantherus Pursh – accepted – fuzzytongue penstemon
  Penstemon eriantherus var. argillosus M.E. Jones – accepted – fuzzytongue penstemon
  Penstemon eriantherus var. cleburnei (M.E. Jones) Dorn – accepted – Cleburn's penstemon
  Penstemon eriantherus var. eriantherus Pursh – accepted – fuzzytongue penstemon, fuzzy-tongue beardtongue
  Penstemon eriantherus var. redactus Pennell & D.D. Keck – accepted – longsac penstemon
  Penstemon eriantherus var. whitedii (Piper) A. Nelson – accepted – Whited's penstemon
  Penstemon euglaucus English – accepted – glaucous beardtongue
  Penstemon fendleri Torr. & A. Gray – accepted – Fendler's beardtongue, Fendler's penstemon
  Penstemon filiformis (D.D. Keck) D.D. Keck – accepted – threadleaf beardtongue, thread-leaved penstemon
  Penstemon flavescens Pennell – accepted – high mountain penstemon
  Penstemon floribundus D. Danley – accepted – Cordelia beardtongue, Cordillia's beardtongue, Cordillia's penstemon
  Penstemon floridus Brandegee – accepted – Panamint penstemon, Panamint beardtongue
  Penstemon floridus ssp. austinii (Eastw.) D.D. Keck – not accepted
  Penstemon floridus var. austinii (Eastw.) N.H. Holmgren – accepted – Austin's beardtongue, Austin's penstemon
  Penstemon floridus var. floridus Brandegee – accepted – Panamint penstemon, Panamint beardtongue
  Penstemon flowersii Neese & S.L. Welsh – accepted – Flowers' beardtongue
  Penstemon francisci-pennellii Crosswh. – not accepted
  Penstemon franklinii S.L. Welsh – accepted – Franklin's penstemon, Ben Franklin's Beardtongue
  Penstemon fremontii Torr. & A. Gray – accepted – Fremont's penstemon, Fremont's beardtongue
  Penstemon fremontii var. fremontii Torr. & A. Gray – accepted – Fremont's beardtongue
  Penstemon fremontii var. glabrescens Dorn & Lichvar – accepted – Fremont's beardtongue
  Penstemon fruticiformis Coville – accepted – Death Valley penstemon, Death Valley beardtongue
  Penstemon fruticiformis ssp. amargosae D.D. Keck – not accepted – Death Valley beardtongue, Amargosa penstemon
  Penstemon fruticiformis ssp. fruticiformis Coville – not accepted – Death Valley beardtongue
  Penstemon fruticiformis var. amargosae (D.D. Keck) N.H. Holmgren – accepted – Death Valley beardtongue
  Penstemon fruticiformis var. fruticiformis Coville – accepted – beardtongue
  Penstemon fruticosus (Pursh) Greene – accepted – bush penstemon
  Penstemon fruticosus ssp. scouleri (Lindl.) Pennell & D.D. Keck – not accepted
  Penstemon fruticosus ssp. serratus D.D. Keck – not accepted
  Penstemon fruticosus var. fruticosus (Pursh) Greene – accepted – bush penstemon
  Penstemon fruticosus var. scouleri (Lindl.) Cronquist – accepted – littleleaf bush penstemon
  Penstemon fruticosus var. serratus (D.D. Keck) Cronquist – accepted – sawleaf bush penstemon
  Penstemon gairdneri Hook. – accepted – Gairdner's beardtongue
  Penstemon gairdneri ssp. hians (Piper) D.D. Keck – not accepted
  Penstemon gairdneri ssp. oreganus (A. Gray) D.D. Keck – not accepted
  Penstemon gairdneri var. gairdneri Hook. – accepted – Gairdner's beardtongue
  Penstemon gairdneri var. hians Piper – not accepted
  Penstemon gairdneri var. oreganus A. Gray – accepted – Gairdner's beardtongue
  Penstemon garrettii Pennell – not accepted – Garrett's beardtongue
  Penstemon gentianoides (Kunth) Poir. – accepted – gentian beardtongue
  Penstemon gibbensii Dorn – accepted – Gibbens' beardtongue, Gibbens beardtongue
  Penstemon glaber Pursh – accepted – western smooth beardtongue, sawsepal penstemon
  Penstemon glaber var. alpinus (Torr.) A. Gray – accepted – alpine sawsepal penstemon, alpine penstemon
  Penstemon glaber var. brandegeei (Porter) C.C. Freeman – accepted – Brandegee's penstemon
  Penstemon glaber var. glaber Pursh – accepted – sawsepal penstemon, western smooth beardtongue
  Penstemon glandulosus Douglas – accepted – stickystem penstemon
  Penstemon glandulosus ssp. chelanensis D.D. Keck – not accepted
  Penstemon glandulosus var. chelanensis (D.D. Keck) Cronquist – accepted – stickystem penstemon
  Penstemon glandulosus var. glandulosus Douglas – accepted – stickystem penstemon
  Penstemon glaucinus Pennell – accepted – blueleaf beardtongue
  Penstemon glaucus Graham – not accepted
  Penstemon globosus (Piper) Pennell & D.D. Keck – accepted – globe penstemon
  Penstemon goodrichii N.H. Holmgren – accepted – Lapoint beardtongue
  Penstemon gormanii Greene – accepted – Gorman's beardtongue
  Penstemon gracilentus A. Gray – accepted – slender penstemon
  Penstemon gracilis Nutt. – accepted – slender penstemon, lilac penstemon, slender beardtongue
  Penstemon gracilis ssp. wisconsinensis (Pennell) Pennell – not accepted
  Penstemon gracilis var. gracilis Nutt. – not accepted – lilac beardtongue, lilac penstemon
  Penstemon gracilis var. wisconsinensis (Pennell) Fassett – not accepted – Wisconsin penstemon
  Penstemon grahamii D.D. Keck – accepted – Uinta Basin beardtongue, Graham's beardtongue
  Penstemon grandiflorus Nutt. – accepted – largeflowered penstemon, large beardtongue
  Penstemon griffinii A. Nelson – accepted – Griffin's beardtongue
  Penstemon grinnellii Eastw. – accepted – Grinnell's beardtongue
  Penstemon grinnellii ssp. grinnellii Eastw. – not accepted – Grinnell's beardtongue
  Penstemon grinnellii ssp. scrophularioides (M.E. Jones) Munz – not accepted – Grinnell's beardtongue
  Penstemon grinnellii var. grinnellii Eastw. – not accepted – beardtongue
  Penstemon grinnellii var. scrophularioides (M.E. Jones) N.H. Holmgren – not accepted – Grinnell's beardtongue
  Penstemon guadalupensis A. Heller – accepted – Guadalupe beardtongue
  Penstemon guadalupensis var. ernstii (Pennell) Cory – not accepted
  Penstemon hallii A. Gray – accepted – Hall's beardtongue
  Penstemon harbourii A. Gray – accepted – Harbour's beardtongue
  Penstemon harringtoni Penland – not accepted
  Penstemon harringtonii Penland – accepted – Harrington's beardtongue, Harrington beardtongue
  Penstemon hartwegii Benth. – accepted – Hartweg's beardtongue
  Penstemon harvardii A. Gray – not accepted
  Penstemon havardii A. Gray – accepted – Big Bend beardtongue
  Penstemon haydenii S. Watson – accepted – blowout penstemon, blowout beardtongue
  Penstemon helleri Small – not accepted
  Penstemon hesperius M. Peck – not accepted
  Penstemon heterodoxus A. Gray – accepted – Sierra penstemon, Sierra beardtongue
  Penstemon heterodoxus ssp. cephalophorus (Greene) D.D. Keck – not accepted
  Penstemon heterodoxus ssp. heterodoxus A. Gray – not accepted – Sierran beardtongue
  Penstemon heterodoxus var. cephalophorus (Greene) N.H. Holmgren – accepted – Sierra beardtongue
  Penstemon heterodoxus var. heterodoxus A. Gray – accepted – Sierra beardtongue
  Penstemon heterodoxus var. shastensis (D.D. Keck) N.H. Holmgren – accepted – Shasta beardtongue
  Penstemon heterophyllus Lindl. – accepted – bunchleaf penstemon
  Penstemon heterophyllus ssp. australis (Munz & I.M. Johnst.) D.D. Keck – not accepted – foothill beardtongue
  Penstemon heterophyllus ssp. heterophyllus Lindl. – not accepted – bunchleaf penstemon
  Penstemon heterophyllus ssp. purdyi D.D. Keck – not accepted – Purdy's penstemon
  Penstemon heterophyllus var. australis Munz & I.M. Johnst. – accepted – foothill beardtongue
  Penstemon heterophyllus var. heterophyllus Lindl. – accepted – buchleaf penstemon
  Penstemon heterophyllus var. purdyi (D.D. Keck) McMinn – accepted – Purdy's penstemon
  Penstemon hirsutus (L.) Willd. – accepted – hairy beardtongue
  Penstemon hirsutus var. hirsutus (L.) Willd. – not accepted – hairy beardtongue
  Penstemon hirsutus var. minimus R.W. Benn. – not accepted
  Penstemon hirsutus var. pygmaeus R.W. Benn. – not accepted
  Penstemon holmgrenii S.L. Clark – not accepted
  Penstemon humilis Nutt. ex A. Gray – accepted – low penstemon, low beardtongue
  Penstemon humilis ssp. brevifolius (A. Gray) D.D. Keck – not accepted – low beardtongue
  Penstemon humilis ssp. humilis Nutt. ex A. Gray – not accepted – low penstemon, low beardtongue
  Penstemon humilis ssp. obtusifolius (Pennell) D.D. Keck – not accepted – low beardtongue
  Penstemon humilis var. brevifolius A. Gray – accepted – low beardtongue
  Penstemon humilis var. deserticus S.L. Welsh – not accepted
  Penstemon humilis var. humilis Nutt. ex A. Gray – accepted – low beardtongue
  Penstemon humilis var. obtusifolius (Pennell) Reveal – accepted – low beardtongue
  Penstemon idahoensis N.D. Atwood & S.L. Welsh – accepted – Idaho beardtongue
  Penstemon immanifestus N.H. Holmgren – accepted – Steptoe Valley penstemon, Steptoe Valley beardtongue
  Penstemon incertus Brandegee – accepted – Mojave beardtongue
  Penstemon inflatus Crosswh. – accepted – inflated beardtongue
  Penstemon jamesii Benth. – accepted – James' penstemon, James' beardtongue
  Penstemon jamesii ssp. breviculus D.D. Keck – not accepted
  Penstemon jamesii ssp. ophianthus (Pennell) D.D. Keck – not accepted
  Penstemon jamesii ssp. typicus D.D. Keck – not accepted
  Penstemon jamesii var. jamesii Benth. – not accepted
  Penstemon janishiae N.H. Holmgren – accepted – Janish's penstemon, Antelope Valley beardtongue
  Penstemon jonesi Pennell – not accepted
  Penstemon keckii Clokey – not accepted
  Penstemon kingii S. Watson – accepted – King's penstemon, King's beardtongue
  Penstemon labrosus (A. Gray) Mast. ex Hook. f. – accepted – San Gabriel beardtongue
  Penstemon laetus A. Gray – accepted – mountain blue penstemon
  Penstemon laetus ssp. laetus A. Gray – not accepted – mountain blue penstemon
  Penstemon laetus ssp. leptosepalus (Greene ex A. Gray) D.D. Keck – not accepted – mountain blue penstemon
  Penstemon laetus ssp. roezlii (Regel) D.D. Keck – not accepted – Roezl's penstemon
  Penstemon laetus ssp. sagittatus D.D. Keck – not accepted – mountain blue penstemon
  Penstemon laetus var. laetus A. Gray – accepted – beardtongue
  Penstemon laetus var. leptosepalus Greene ex A. Gray – accepted
  Penstemon laetus var. roezlii (Regel) Jeps. – not accepted
  Penstemon laetus var. sagittatus (D.D. Keck) McMinn – accepted
  Penstemon laevigatus Aiton – accepted – eastern smooth beardtongue
  Penstemon laevigatus ssp. alluviorum (Pennell) R.W. Benn. – not accepted
  Penstemon laevigatus ssp. calycosus (Small) R.W. Benn. – not accepted
  Penstemon laevigatus ssp. deamii (Pennell) R.W. Benn. – not accepted
  Penstemon laevigatus ssp. digitalis (Nutt. ex Sims) R.W. Benn. – not accepted
  Penstemon laevigatus var. angulatus R.W. Benn. – not accepted
  Penstemon laevigatus var. deamii (Pennell) R.W. Benn. – not accepted
  Penstemon laevis Pennell – accepted – southwestern penstemon, southwestern beardtongue
  Penstemon lanceolatus Benth. – accepted – lanceleaf beardtongue
  Penstemon laricifolius Hook. & Arn. – accepted – larchleaf beardtongue
  Penstemon laricifolius ssp. exilifolius (A. Nelson) D.D. Keck – not accepted – larchleaf beardtongue
  Penstemon laricifolius ssp. laricifolius Hook. & Arn. – not accepted – larchleaf beardtongue
  Penstemon laricifolius var. exilifolius (A. Nelson) Payson – accepted – larchleaf beardtongue
  Penstemon laricifolius var. laricifolius Hook. & Arn. – accepted – larchleaf beardtongue
  Penstemon laxiflorus Pennell – accepted – nodding beardtongue
  Penstemon laxus A. Nelson – accepted – tufted penstemon
  Penstemon leiophyllus Pennell – accepted – smoothleaf penstemon, smoothleaf beardtongue
  Penstemon leiophyllus var. francisci-pennellii (Crosswh.) N.H. Holmgren – accepted – smoothleaf beardtongue, smoothleaf penstemon
  Penstemon leiophyllus var. keckii (Clokey) N.H. Holmgren – accepted – Keck's beardtongue, Keck's penstemon
  Penstemon leiophyllus var. leiophyllus Pennell – accepted – smoothleaf beardtongue, smoothleaf penstemon
  Penstemon lemhiensis (D.D. Keck) D.D. Keck & Cronquist – accepted – Lemhi penstemon, Lemhi beardtongue
  Penstemon lemmonii A. Gray – not accepted
  Penstemon lentus Pennell – accepted – handsome penstemon, handsome beardtongue
  Penstemon lentus ssp. albiflorus D.D. Keck – not accepted
  Penstemon lentus var. albiflorus (D.D. Keck) Reveal – accepted – handsome beardtongue
  Penstemon lentus var. lentus Pennell – accepted – handsome beardtongue
  Penstemon leonardii Rydb. – accepted – Leonard's penstemon, Leonard's beardtongue
  Penstemon leonardii var. higginsii Neese – accepted – Higgins' beardtongue
  Penstemon leonardii var. leonardii Rydb. – accepted – Leonard's beardtongue
  Penstemon leonardii var. patricus (N.H. Holmgren) Neese – accepted – Leonard's beardtongue, Leonard's penstemon
  Penstemon leptanthus Pennell – not accepted – Sevier Plateau beardtongue
  Penstemon linarioides A. Gray – accepted – creeping penstemon, toadflax penstemon
  Penstemon linarioides ssp. coloradoensis (A. Nelson) D.D. Keck – accepted – toadflax penstemon, Colorado penstemon
  Penstemon linarioides ssp. compactifolius D.D. Keck – not accepted – compact-leaf penstemon, toadflax penstemon, toadflax beardtongue
  Penstemon linarioides ssp. linarioides A. Gray – accepted – toadflax penstemon, toadflax beardtongue
  Penstemon linarioides ssp. maguirei D.D. Keck – accepted – Maguire's penstemon
  Penstemon linarioides ssp. sileri (A. Gray) D.D. Keck – accepted – Siler's penstemon
  Penstemon linarioides ssp. taosensis D.D. Keck – not accepted
  Penstemon linarioides ssp. typicus D.D. Keck – not accepted
  Penstemon linarioides var. sileri A. Gray – not accepted
  Penstemon linarioides var. viridis D.D. Keck – not accepted
  Penstemon longiflorus (Pennell) S.L. Clark – accepted – longflower penstemon
  Penstemon lyallii A. Gray – accepted – Lyall's beardtongue
  Penstemon macranthus Eastw. – not accepted
  Penstemon maguirei Crosswh. – not accepted
  Penstemon marcusii (D.D. Keck) N.H. Holmgren – accepted – Marcus' beardtongue, Jones' beardtongue
  Penstemon mensarum Pennell – accepted – tiger beardtongue
  Penstemon menziesii Hook. – not accepted
  Penstemon menziesii ssp. davidsonii (Greene) Piper – not accepted
  Penstemon menziesii ssp. thompsonii Pennell & D.D. Keck – not accepted
  Penstemon metcalfei Wooton & Standl. – accepted – Metcalfe's beardtongue
  Penstemon microphyllus A. Gray – not accepted
  Penstemon minidokanus A. Nelson & J.F. Macbr. – not accepted
  Penstemon miser A. Gray – accepted – Malheur penstemon
  Penstemon modestus Greene – not accepted
  Penstemon moffatii Eastw. – accepted – Moffatt's beardtongue
  Penstemon moffatii ssp. marcusii D.D. Keck – not accepted
  Penstemon moffatii ssp. moffatii Eastw. – not accepted – Moffatt's beardtongue
  Penstemon moffatii ssp. paysonii (Pennell) D.D. Keck – not accepted – Moffatt's beardtongue
  Penstemon monoensis A. Heller – accepted – Mono penstemon
  Penstemon montanus Greene – accepted – cordroot beardtongue
  Penstemon montanus ssp. idahoensis D.D. Keck – not accepted
  Penstemon montanus var. idahoensis (D.D. Keck) Cronquist – accepted – Central Idaho penstemon
  Penstemon montanus var. montanus Greene – accepted – cordroot beardtongue
  Penstemon moriahensis N.H. Holmgren – accepted – Mount Moriah penstemon, Mt. Moriah beardtongue
  Penstemon mucronatus N.H. Holmgren – accepted – Sheep Creek beardtongue, mucronate penstemon
  Penstemon multicaulis Pennell – not accepted
  Penstemon multiflorus (Benth) Chapm. ex Small – accepted – manyflower beardtongue
  Penstemon murcronatus N.H. Holmgren – not accepted
  Penstemon murrayanus Hook. – accepted – scarlet beardtongue
  Penstemon nanus D.D. Keck – accepted – dwarf beardtongue, low beardtongue
  Penstemon navajoa N.H. Holmgren – accepted – Navajo Mountain beardtongue
  Penstemon nemorosus (Douglas ex Lindl.) Trautv. – not accepted
  Penstemon neomexicanus Wooton & Standl. – accepted – New Mexico beardtongue
  Penstemon neotericus D.D. Keck – accepted – Plumas County beardtongue
  Penstemon newberryi A. Gray – accepted – pride-of-the-mountains, mountain pride
  Penstemon newberryi ssp. berryi (Eastw.) D.D. Keck – not accepted – Berry's penstemon
  Penstemon newberryi ssp. newberryi A. Gray – not accepted – Newberry's penstemon, mountain pride
  Penstemon newberryi ssp. sonomensis (Greene) D.D. Keck – not accepted – Sonoma penstemon
  Penstemon newberryi var. berryi (Eastw.) N.H. Holmgren – accepted – Berry's penstemon
  Penstemon newberryi var. newberryi A. Gray – accepted – beardtongue
  Penstemon newberryi var. sonomensis (Greene) Jeps. – accepted – Sonoma penstemon
  Penstemon nitidus Douglas ex Benth. – accepted – waxleaf penstemon
  Penstemon nitidus ssp. polyphyllus Pennell – not accepted
  Penstemon nitidus var. nitidus Douglas ex Benth. – accepted – waxleaf penstemon
  Penstemon nitidus var. polyphyllus (Pennell) Cronquist – accepted – waxleaf penstemon
  Penstemon nudiflorus A. Gray – accepted – Flagstaff beardtongue
  Penstemon nyeensis Crosswh. – not accepted
  Penstemon oklahomensis Pennell – accepted – Oklahoma penstemon, Oklahoma beardtongue
  Penstemon oliganthus Wooton & Standl. – accepted – Apache beardtongue
  Penstemon ophianthus Pennell – accepted – coiled anther penstemon, Arizona beardtongue
  Penstemon oreocharis Greene – not accepted
  Penstemon osterhoutii Pennell – accepted – Osterhout's beardtongue
  Penstemon ovatus Douglas ex Hook. – accepted – eggleaf beardtongue
  Penstemon ovatus var. pinetorum Piper – not accepted
  Penstemon pachyphyllus A. Gray ex Rydb. – accepted – thickleaf penstemon, thickleaf beardtongue
  Penstemon pachyphyllus ssp. congestus (M.E. Jones) D.D. Keck – not accepted
  Penstemon pachyphyllus var. congestus (M.E. Jones) N.H. Holmgren – accepted – thickleaf beardtongue, thickleaf penstemon
  Penstemon pachyphyllus var. mucronatus (N.H. Holmgren) Neese – not accepted – mucronate penstemon
  Penstemon pachyphyllus var. pachyphyllus A. Gray ex Rydb. – accepted – thickleaf beardtongue
  Penstemon pahutensis N.H. Holmgren – accepted – Pahute penstemon, Paiute beardtongue
  Penstemon pallidus Small – accepted – pale beardtongue
  Penstemon pallidus ssp. arkansanus (Pennell) R.W. Benn. – not accepted
  Penstemon palmeri A. Gray – accepted – Palmer's penstemon
  Penstemon palmeri ssp. eglandulosus D.D. Keck – not accepted
  Penstemon palmeri ssp. typicus D.D. Keck – not accepted
  Penstemon palmeri var. eglandulosus (D.D. Keck) N.H. Holmgren – accepted – scented beardtongue, scented penstemon
  Penstemon palmeri var. macranthus (Eastw.) N.H. Holmgren – accepted – scented beardtongue, scented penstemon
  Penstemon palmeri var. palmeri A. Gray – accepted – Palmer's penstemon
  Penstemon papillatus J.T. Howell – accepted – Inyo beardtongue, Inyo penstemon
  Penstemon parryi (A. Gray) A. Gray – accepted – Parry's penstemon, Parry's beardtongue
  Penstemon parviflorus Pennell – not accepted – Montezuma County beardtongue
  Penstemon parvulus (A. Gray) Krautter – accepted – azure penstemon
  Penstemon parvus Pennell – accepted – Aquarius Plateau beardtongue, small beardtongue
  Penstemon patens (M.E. Jones) N.H. Holmgren – accepted – Lone Pine penstemon, Lone Pine beardtongue
  Penstemon patricus N.H. Holmgren – not accepted
  Penstemon pauciflorus auct. non Greene – not accepted
  Penstemon payettensis A. Nelson & J.F. Macbr. – accepted – Payette beardtongue
  Penstemon paysoniorum D.D. Keck – accepted – Payson's beardtongue, Payson beardtongue
  Penstemon peckii Pennell – accepted – Peck's beardtongue
  Penstemon penlandii W.A. Weber – accepted – Penland's beardtongue, Penland beardtongue
  Penstemon pennellianus D.D. Keck – accepted – Blue Mountain beardtongue
  Penstemon penstemon (L.) Britton – not accepted
  Penstemon perpulcher A. Nelson – accepted – Minidoka beardtongue
  Penstemon personatus D.D. Keck – accepted – closethroat beardtongue, closed-lip beardtongue
  Penstemon petiolatus Brandegee – accepted – lime penstemon, petiolate beardtongue
  Penstemon pinifolius Greene – accepted – pineneedle penstemon, pineneedle beardtongue
  Penstemon pinorum L.M. Shultz & J.S. Shultz – accepted – Pine Valley penstemon
  Penstemon platyphyllus Rydb. – accepted – broadleaf penstemon, broadleaf beardtongue
  Penstemon pratensis Greene – accepted – western whiteflower penstemon, western whiteflower beardtongue
  Penstemon procerus Douglas ex Graham – accepted – pincushion beardtongue, littleflower penstemon
  Penstemon procerus ssp. aberrans (M.E. Jones) D.D. Keck – not accepted
  Penstemon procerus ssp. brachyanthus (Pennell) D.D. Keck – not accepted
  Penstemon procerus ssp. formosus (A. Nelson) D.D. Keck – not accepted
  Penstemon procerus ssp. modestus (Greene) D.D. Keck – not accepted
  Penstemon procerus ssp. tolmiei (Hook.) D.D. Keck – not accepted
  Penstemon procerus var. aberrans (M.E. Jones) A. Nelson – accepted – pincushion beardtongue
  Penstemon procerus var. brachyanthus (Pennell) Cronquist – accepted – pincushion beardtongue
  Penstemon procerus var. formosus (A. Nelson) Cronquist – accepted – pincushion beardtongue, pincushion penstemon
  Penstemon procerus var. modestus (Greene) N.H. Holmgren – accepted – pincushion beardtongue, pincushion penstemon
  Penstemon procerus var. procerus Douglas ex Graham – accepted – pincushion beardtongue
  Penstemon procerus var. tolmiei (Hook.) Cronquist – accepted – Tolmie's penstemon
  Penstemon pruinosus Douglas ex Lindl. – accepted – Chilean beardtongue, Chelan beardtongue
  Penstemon pseudoparvus Crosswh. – not accepted – Mt. Washington beardtongue
  Penstemon pseudoputus (Crosswh.) N.H. Holmgren – accepted – Kaibab Plateau beardtongue
  Penstemon pseudospectabilis M.E. Jones – accepted – desert penstemon
  Penstemon pseudospectabilis ssp. connatifolius (A. Nelson) D.D. Keck – accepted – desert penstemon, desert beardtongue
  Penstemon pseudospectabilis ssp. pseudospectabilis M.E. Jones – accepted – desert beardtongue, desert penstemon
  Penstemon pseudospectabilis ssp. typicus D.D. Keck – not accepted
  Penstemon puberulentus Rydb. – not accepted
  Penstemon pudicus Reveal & Beatley – accepted – bashful penstemon, Kawich Range beardtongue
  Penstemon pulchellus Lindl. – not accepted
  Penstemon pumilus Nutt. – accepted – Salmon River beardtongue
  Penstemon purpusii Brandegee – accepted – Snow Mountain beardtongue
  Penstemon putus A. Nelson – accepted – Black River beardtongue
  Penstemon radicosus A. Nelson – accepted – matroot penstemon
  Penstemon ramosus Crosswh. – not accepted – lanceleaf beardtongue, lanceleaf penstemon
  Penstemon rattanii A. Gray – accepted – Rattan's beardtongue
  Penstemon rattanii ssp. kleei (Greene) D.D. Keck – not accepted – Santa Cruz Mountains beardtongue
  Penstemon rattanii ssp. rattanii A. Gray – not accepted – Rattan's beardtongue
  Penstemon rattanii var. kleei (Greene) A. Gray – accepted
  Penstemon rattanii var. minor A. Gray – not accepted
  Penstemon rattanii var. rattanii A. Gray – accepted – beardtongue
  Penstemon retrorsus Payson ex Pennell – accepted – Adobe Hills beardtongue
  Penstemon retrosus Payson ex Pennell – not accepted
  Penstemon rhizomatosus N.H. Holmgren – accepted – Scheel Creek beardtongue
  Penstemon richardsonii Douglas ex Lindl. – accepted – cutleaf beardtongue
  Penstemon richardsonii ssp. curtiflorus D.D. Keck – not accepted
  Penstemon richardsonii ssp. dentatus D.D. Keck – not accepted
  Penstemon richardsonii var. curtiflorus (D.D. Keck) Cronquist – accepted – cutleaf beardtongue
  Penstemon richardsonii var. dentatus (D.D. Keck) Cronquist – accepted – cutleaf beardtongue
  Penstemon richardsonii var. richardsonii Douglas ex Lindl. – accepted – Richardson's penstemon
  Penstemon roezlii Regel – accepted – Roezl's penstemon
  Penstemon rostriflorus Kellogg – accepted – Bridges' penstemon, beaked beardtongue, beakflower penstemon
  Penstemon rothrockii A. Gray – not accepted
  Penstemon rothrockii ssp. jacintensis (Abrams) D.D. Keck – not accepted
  Penstemon rubicundus D.D. Keck – accepted – Wassuck penstemon, Wassuk Range beardtongue
  Penstemon rupicola (Piper) Howell – accepted – cliff beardtongue
  Penstemon rydbergii A. Nelson – accepted – meadow beardtongue, Rydberg's penstemon
  Penstemon rydbergii ssp. aggregatus (Pennell) D.D. Keck – not accepted
  Penstemon rydbergii var. aggregatus (Pennell) N.H. Holmgren – accepted – meadow beardtongue, meadow penstemon
  Penstemon rydbergii var. oreocharis (Greene) N.H. Holmgren – accepted – herbaceous penstemon
  Penstemon rydbergii var. rydbergii A. Nelson – accepted – swollen penstemon
  Penstemon rydbergii var. varians (A. Nelson) Cronquist – not accepted
  Penstemon saxosorum Pennell – accepted – upland beardtongue
  Penstemon scapoides D.D. Keck – accepted – pinyon beardtongue
  Penstemon scariosus Pennell – accepted – White River beardtongue
  Penstemon scariosus var. albifluvis (England) N.H. Holmgren – accepted – White River beardtongue
  Penstemon scariosus var. cyanomontanus Neese – accepted – Neese's Blue Mountain beardtongue
  Penstemon scariosus var. garrettii (Pennell) N.H. Holmgren – accepted – Garrett's beardtongue
  Penstemon scariosus var. scariosus Pennell – accepted – White River beardtongue
  Penstemon scouleri Lindl. – not accepted
  Penstemon secundiflorus Benth. – accepted – sidebells penstemon
  Penstemon seorsus (A. Nelson) D.D. Keck – accepted – shortlobe penstemon
  Penstemon sepalulus A. Nelson – accepted – littlecup beardtongue
  Penstemon serrulatus Menzies ex Rees – accepted – serrulate penstemon
  Penstemon shastensis D.D. Keck – not accepted
  Penstemon smallii A. Heller – accepted – Small's beardtongue
  Penstemon spatulatus Pennell – accepted – Wallowa beardtongue
  Penstemon speciosus Douglas ex Lindl. – accepted – prairie-clover, royal penstemon
  Penstemon speciosus ssp. kennedyi (A. Nelson) D.D. Keck – not accepted
  Penstemon speciosus ssp. lemhiensis D.D. Keck – not accepted
  Penstemon speciosus var. speciosus Douglas ex Lindl. – not accepted
  Penstemon spectabilis Thurb. ex A. Gray – accepted – showy penstemon
  Penstemon spectabilis ssp. spectabilis Thurb. ex A. Gray – not accepted – showy penstemon
  Penstemon spectabilis ssp. subviscosus D.D. Keck – not accepted – showy penstemon
  Penstemon spectabilis var. spectabilis Thurb. ex A. Gray – accepted – showy penstemon
  Penstemon spectabilis var. subviscosus (D.D. Keck) McMinn – accepted – showy penstemon
  Penstemon spinulosus Wooton & Standl. – not accepted
  Penstemon stenophyllus A. Gray – accepted – Sonoran beardtongue
  Penstemon stephensii Brandegee – accepted – Stephens' penstemon, Stephens' beardtongue
  Penstemon strictiformis Rydb. – accepted – stiff penstemon, Mancos penstemon
  Penstemon strictus Benth. – accepted – Rocky Mountain beardtongue, Rocky Mountain penstemon
  Penstemon strictus ssp. angustus Pennell – not accepted
  Penstemon strictus ssp. strictiformis (Rydb.) D.D. Keck – not accepted
  Penstemon strictus var. strictus Benth. – not accepted
  Penstemon subglaber Rydb. – accepted – smooth penstemon
  Penstemon subserratus Pennell – accepted – finetooth beardtongue
  Penstemon subulatus M.E. Jones – accepted – hackberry beardtongue
  Penstemon sudans M.E. Jones – accepted – Susanville beardtongue, Susanville penstemon
  Penstemon suffrutescens Rydb. – not accepted
  Penstemon superbus A. Nelson – accepted – superb beardtongue
  Penstemon tenuiflorus Pennell – accepted – eastern whiteflower beardtongue
  Penstemon tenuis Small – accepted – sharpsepal beardtongue
  Penstemon ternatus Torr. ex A. Gray – not accepted
  Penstemon ternatus ssp. septentrionalis (Munz & I.M. Johnst.) D.D. Keck – not accepted
  Penstemon teucrioides Greene – accepted – germander beardtongue
  Penstemon thompsoniae (A. Gray) Rydb. – accepted – Thompson's penstemon, Thompson's beardtongue
  Penstemon thompsoniae ssp. jaegeri D.D. Keck – not accepted – Jaeger's beardtongue, Jaeger's penstemon
  Penstemon thompsoniae ssp. thompsoniae (A. Gray) Rydb. – not accepted – Thompson's penstemon, Thompson's beardtongue
  Penstemon thompsoniae var. desperatus Neese – not accepted
  Penstemon thurberi Torr. – accepted – Thurber's penstemon
  Penstemon thurberi var. anestius Reveal & Beatley – not accepted
  Penstemon tidestromii Pennell – accepted – Tidestrom's beardtongue, Tidestrom beardtongue
  Penstemon tiehmii N.H. Holmgren – accepted – Tiehm's beardtongue
  Penstemon tolmiei Hook. – not accepted
  Penstemon tolmiei ssp. brachyanthus (Pennell) D.D. Keck – not accepted
  Penstemon tolmiei ssp. formosus (A. Nelson) D.D. Keck – not accepted
  Penstemon torreyi Benth. – not accepted
  Penstemon tracyi D.D. Keck – accepted – Trinity penstemon, Tracy beardtongue
  Penstemon triflorus A. Heller – accepted – Heller's beardtongue
  Penstemon triflorus ssp. integrifolius Pennell – not accepted – Heller's beardtongue
  Penstemon triflorus ssp. triflorus A. Heller – not accepted – Heller's beardtongue
  Penstemon triflorus var. integrifolius (Pennell) Cory – accepted – Heller's beardtongue
  Penstemon triflorus var. triflorus A. Heller – accepted – Heller's beardtongue
  Penstemon triphyllus Douglas ex Lindl. – accepted – Riggin's penstemon
  Penstemon triphyllus ssp. diphyllus (Rydb.) D.D. Keck – not accepted
  Penstemon tubiflorus Nutt. – accepted – white wand beardtongue
  Penstemon tubiflorus var. achoreus Fernald – not accepted – white wand beardtongue
  Penstemon tubiflorus var. tubiflorus Nutt. – not accepted – white wand beardtongue
  Penstemon tusharensis N.H. Holmgren – accepted – Tushar Range beardtongue
  Penstemon uintahensis Pennell – accepted – Uinta Mountain beardtongue, Uintah beardtongue
  Penstemon unilateralis Rydb. – not accepted – oneside penstemon
  Penstemon utahensis Eastw. – accepted – Utah penstemon
  Penstemon variabilis Suksd. – not accepted
  Penstemon vaseyanus Greene – not accepted
  Penstemon venosus (D.D. Keck) Reveal – not accepted
  Penstemon venustus Douglas ex Lindl. – accepted – Venus penstemon
  Penstemon versicolor Pennell – accepted – variable-color beardtongue
  Penstemon virens Pennell ex Rydb. – accepted – Front Range beardtongue
  Penstemon virgatus A. Gray – accepted – upright blue beardtongue
  Penstemon virgatus ssp. arizonicus (A. Gray) D.D. Keck – not accepted
  Penstemon virgatus ssp. asa-grayi Crosswh. – not accepted
  Penstemon virgatus ssp. pseudoputus Crosswh. – not accepted
  Penstemon virgatus ssp. putus (A. Nelson) Crosswh. – not accepted
  Penstemon virgatus var. asa-grayi (Crosswh.) Dorn – accepted – upland blue beardtongue
  Penstemon virgatus var. virgatus A. Gray – accepted – upright blue beardtongue
  Penstemon wardii A. Gray – accepted – Ward's beardtongue, Ward beardtongue
  Penstemon washingtonensis D.D. Keck – accepted – Washington beardtongue
  Penstemon watsonii A. Gray – accepted – Watson's beardtongue, Watson's penstemon
  Penstemon watsonii ssp. laxus (A. Nelson) D.D. Keck – not accepted
  Penstemon wherryi Pennell – not accepted
  Penstemon whippleanus A. Gray – accepted – dark beardtongue, Whipple's penstemon
  Penstemon whitedii Piper – not accepted
  Penstemon whitedii ssp. dayanus (Howell) D.D. Keck – not accepted
  Penstemon whitedii ssp. tristis Pennell & D.D. Keck – not accepted
  Penstemon wilcoxii Rydb. – accepted – Wilcox's penstemon
  Penstemon wisconsinensis Pennell – not accepted
  Penstemon wrightii Hook. – accepted – Wright's beardtongue
  Penstemon X bryantiae D.D. Keck (pro. hybr.) – accepted – Bryant's beardtongue
  Penstemon X crideri A. Nelson (pro. sp.) – accepted – Crider's penstemon
  Penstemon X dubius Davidson (pro. sp.) – accepted – dubius penstemon
  Penstemon X jonesii Pennell (pro. sp.) – accepted – Jones' penstemon
  Penstemon X mirus A. Nelson (pro. sp.) – accepted – bush penstemon
  Penstemon X parishii A. Gray (pro. sp.) – accepted – Parish's penstemon
  Penstemon X peirsonii Munz & I.M. Johnst. (pro. sp.) – accepted – Peirson's penstemon
  Penstemon yampaensis Penland – accepted – Yampa beardtongue
  Salvia penstemonoides Kunth & Bouché – accepted – big red sage
   

A gray graphic bar
Search on:  Any Name or TSN  Common Name  Scientific Name  TSN
In:  Kingdom    

A gray bar