- Penstemon abietinus, Firleaf beardtongue
- Penstemon absarokensis, Absaroka Range beardtongue
- Penstemon acaulis, Stemless beardtongue
- Penstemon acuminatus, Sharpleaf penstemon
- Penstemon alamosensis, Los Alamos beardtongue
- Penstemon albertinus, Alberta beardtongue
- Penstemon albidus, White penstemon
- Penstemon albifluvis
- Penstemon albomarginatus, Whitemargin beardtongue
- Penstemon alluviorum, Lowland Beardtongue
- Penstemon alpinus
- Penstemon ambiguus, Gilia beardtongue
- Penstemon ammophilus, Sandloving penstemon
- Penstemon anguineus, Siskiyou beardtongue
- Penstemon angustifolius, Broadbeard beardtongue
- Penstemon antirrhinoides
- Penstemon arenarius, Nevada sanddune beardtongue
- Penstemon arenicola, Sand penstemon
- Penstemon aridus, Stiffleaf penstemon
- Penstemon arkansanus, Arkansas beardtongue
- Penstemon attenuatus, Sulphur penstemon
- Penstemon atwoodii, Kaiparowits beardtongue
- Penstemon auriberbis, Colorado beardtongue
- Penstemon australis, Eustis Lake Beardtongue
- Penstemon azureus, Azure penstemon
- Penstemon baccharifolius, Baccharisleaf beardtongue
- Penstemon barbatus, Beardlip penstemon
- Penstemon barnebyi, White River Valley beardtongue
- Penstemon barrettiae, Barretts beardtongue
- Penstemon bicolor, Pinto beardtongue
- Penstemon bracteatus, Red Canyon beardtongue
- Penstemon breviculus, Shortstem beardtongue
- Penstemon brittonorum
- Penstemon buckleyi, Buckleys beardtongue
- Penstemon caesius, San Bernardino beardtongue
- Penstemon caespitosus, Mat penstemon
- Penstemon calcareus, Limestone beardtongue
- Penstemon californicus, California penstemon
- Penstemon calycosus, Longsepal beardtongue
- Penstemon canescens, Eastern gray beardtongue
- Penstemon cardinalis, Cardinal beardtongue
- Penstemon cardwellii, Cardwells beardtongue
- Penstemon carnosus, Fleshy beardtongue
- Penstemon caryi, Carys beardtongue
- Penstemon centranthifolius, Scarlet bugler
- Penstemon cerrosensis
- Penstemon cinereus
- Penstemon cinicola, Ash penstemon
- Penstemon cleburnei
- Penstemon clevelandii, Clevelands beardtongue
- Penstemon cobaea, Cobaea beardtongue
- Penstemon comarrhenus, Dusty beardtongue
- Penstemon compactus, Compact penstemon
- Penstemon concinnus, Tunnel Springs beardtongue
- Penstemon confertus, Yellow penstemon
- Penstemon confusus, Owens Valley beardtongue
- Penstemon crandallii, Crandalls beardtongue
- Penstemon crideri
- Penstemon cusickii, Cusicks beardtongue
- Penstemon cyananthus, Wasatch beardtongue
- Penstemon cyaneus, Blue penstemon
- Penstemon cyanocaulis, Bluestem beardtongue
- Penstemon cyathophorus, Sagebrush beardtongue
- Penstemon dasyphyllus, Cochise beardtongue
- Penstemon davidsonii, Davidsons penstemon
- Penstemon deamii, Deams beardtongue
- Penstemon deaveri, Mt Graham beardtongue
- Penstemon debilis, Parachute beardtongue
- Penstemon degeneri, Degeners beardtongue
- Penstemon deustus, Scabland penstemon
- Penstemon digitalis, Talus slope penstemon
- Penstemon diphyllus, Twoleaf beardtongue
- Penstemon discolor, Cataiina beardtongue
- Penstemon dissectus, Dissected Beardtongue
- Penstemon distans, Mt Tumbull beardtongue
- Penstemon dolius, Jones beardtongue
- Penstemon duchesnensis
- Penstemon eatonii, Firecracker penstemon
- Penstemon elegantulus, Rockvine penstemon
- Penstemon ellipticus, Rocky ledge penstemon
- Penstemon eriantherus, Fuzzytongue penstemon
- Penstemon euglaucus, Glaucous beardtongue
- Penstemon eximius
- Penstemon fendleri, Fendlers penstemon
- Penstemon filiformis, Threadleaf beardtongue
| - Penstemon flavescens, High mountain penstemon
- Penstemon floribundus, Cordillias beardtongue
- Penstemon floridus, Panamint beardtongue
- Penstemon flowersii, Flowers beardtongue
- Penstemon fremontii, Fremonts beardtongue
- Penstemon fruticiformis, Death Valley beardtongue
- Penstemon fruticosus, Bush penstemon
- Penstemon gairdneri, Gairdners beardtongue
- Penstemon garrettii
- Penstemon gibbensii, Gibbens beardtongue
- Penstemon glaber, Sawsepal penstemon
- Penstemon glandulosus, Stickystem penstemon
- Penstemon glaucinus, Blueleaf beardtongue
- Penstemon globosus, Globe penstemon
- Penstemon goodrichii, Lapoint beardtongue
- Penstemon gormanii, Gormans beardtongue
- Penstemon gracilentus, Slender penstemon
- Penstemon gracilis, Lilac penstemon
- Penstemon grahamii, Uinta Basin beardtongue
- Penstemon grandiflorus, Large beardtongue
- Penstemon grinnellii, Grinnells beardtongue
- Penstemon guadalupensis, Guadalupe beardtongue
- Penstemon hallii, Halls beardtongue
- Penstemon harbourii, Harbours beardtongue
- Penstemon harringtonii, Harringtons beardtongue
- Penstemon havardii, Big Bend beardtongue
- Penstemon haydenii, Blowout beardtongue
- Penstemon helleri
- Penstemon hesperius
- Penstemon heterodoxus, Sierra beardtongue
- Penstemon heterophyllus, Bunchleaf penstemon
- Penstemon hirsutus, Hairy beardtongue
- Penstemon humilis, Low beardtongue
- Penstemon immanifestus, Steptoe Valley beardtongue
- Penstemon incertus, Mojave beardtongue
- Penstemon jamesii, James beardtongue
- Penstemon janishiae, Antelope Valley beardtongue
- Penstemon jonesii
- Penstemon keckii
- Penstemon kingii, Kings beardtongue
- Penstemon labrosus, San Gabriel beardtongue
- Penstemon laetus, Mountain blue penstemon
- Penstemon laevigatus, Eastern smooth beardtongue
- Penstemon laevis, Southwestern beardtongue
- Penstemon laricifolius, Larchleaf beardtongue
- Penstemon laxiflorus, Nodding Beardtongue
- Penstemon laxus, Tufted penstemon
- Penstemon leiophyllus, Smoothleaf beardtongue
- Penstemon lemhiensis, Lemhi penstemon
- Penstemon lentus, Handsome beardtongue
- Penstemon leonardii, Leonards beardtongue
- Penstemon leptanthus, Sevier Plateau beardtongue
- Penstemon linarioides, Toadflax penstemon
- Penstemon longiflorus, Longflower penstemon
- Penstemon lyallii, Lyalls beardtongue
- Penstemon marcusii, Marcus beardtongue
- Penstemon mensarum, Tiger beardtongue
- Penstemon mirus
- Penstemon miser, Malheur penstemon
- Penstemon moffatii, Moffatts beardtongue
- Penstemon monoensis, Mono penstemon
- Penstemon montanus, Cordroot beardtongue
- Penstemon moriahensis, Mt Moriah beardtongue
- Penstemon mucronatus
- Penstemon multiflorus, Manyflower Beardtongue
- Penstemon murrayanus, Scarlet beardtongue
- Penstemon nanus, Dwarf beardtongue
- Penstemon navajoa, Navajo Mountain beardtongue
- Penstemon neomexicanus, New Mexico beardtongue
- Penstemon neotericus, Plumas County beardtongue
- Penstemon newberryi, Mountain pride
- Penstemon nitidus, Waxleaf penstemon
- Penstemon nudiflorus, Flagstaff beardtongue
- Penstemon oklahomensis, Oklahoma beardtongue
- Penstemon oliganthus, Apache beardtongue
- Penstemon ophianthus, Coiled anther penstemon
- Penstemon oreocharis
- Penstemon osterhoutii, Osterhouts beardtongue
- Penstemon ovatus, Eggleaf beardtongue
- Penstemon pachyphyllus, Thickleaf beardtongue
- Penstemon pahutensis, Paiute beardtongue
- Penstemon pallidus, Pale beardtongue
- Penstemon palmeri, Palmers penstemon
- Penstemon papillatus, Inyo beardtongue
- Penstemon parishii
| - Penstemon parryi, Parrys beardtongue
- Penstemon parviflorus, Montezuma County beardtongue
- Penstemon parvulus
- Penstemon parvus, Aquarius Plateau beardtongue
- Penstemon patens, Lone Pine beardtongue
- Penstemon patricus
- Penstemon payettensis, Payette beardtongue
- Penstemon paysoniorum, Paysons beardtongue
- Penstemon peckii, Pecks beardtongue
- Penstemon penlandii, Penlands beardtongue
- Penstemon pennellianus, Blue Mountain beardtongue
- Penstemon pentstemon
- Penstemon perpulcher, Minidoka beardtongue
- Penstemon personatus, Closethroat beardtongue
- Penstemon petiolatus, Petiolate beardtongue
- Penstemon pinifolius, Pineneedle beardtongue
- Penstemon pinorum, Pine Valley penstemon
- Penstemon platyphyllus, Broadleaf beardtongue
- Penstemon pratensis, Western whiteflower beardtongue
- Penstemon procerus, Littleflower penstemon
- Penstemon pruinosus, Chelan beardtongue
- Penstemon pseudoputus, Kaibab Plateau beardtongue
- Penstemon pseudospectabilis, Desert penstemon
- Penstemon pudicus, Kawich Range beardtongue
- Penstemon pumilus, Salmon River beardtongue
- Penstemon purpusii, Snow Mountain beardtongue
- Penstemon putus, Black River beardtongue
- Penstemon radicosus, Matroot penstemon
- Penstemon rattanii, Rattans beardtongue
- Penstemon retrorsus, Adobe Hills beardtongue
- Penstemon richardsonii, Cutleaf beardtongue
- Penstemon roezlii, Roezls penstemon
- Penstemon rostriflorus, Bridge penstemon
- Penstemon rubicundus, Wassuk Range beardtongue
- Penstemon rupicola, Cliff beardtongue
- Penstemon rydbergii, Rydbergs penstemon
- Penstemon saxosorum, Upland beardtongue
- Penstemon scapoides, Pinyon beardtongue
- Penstemon scariosus, White River beardtongue
- Penstemon secundiflorus, Sidebells penstemon
- Penstemon seorsus, Shortlobe penstemon
- Penstemon sepalulus, Littlecup beardtongue
- Penstemon serrulatus, Serrulate penstemon
- Penstemon shastensis
- Penstemon smallii, Smalls penstemon
- Penstemon spatulatus, Wallowa beardtongue
- Penstemon speciosus, Royal penstemon
- Penstemon spectabilis, Showy penstemon
- Penstemon stenophyllus, Sonoran beardtongue
- Penstemon stephensii, Stephens penstemon
- Penstemon strictiformis, Mancos penstemon
- Penstemon strictus, Rocky Mountain penstemon
- Penstemon subglaber, Smooth penstemon
- Penstemon subserratus, Finetooth beardtongue
- Penstemon subulatus, Hackberry beardtongue
- Penstemon sudans, Susanville beardtongue
- Penstemon tenuiflorus, Eastern whiteflower beardtongue
- Penstemon tenuis, Sharpsepal beardtongue
- Penstemon teucrioides, Germander beardtongue
- Penstemon thompsoniae, Thompsons beardtongue
- Penstemon thurberi, Thurbers penstemon
- Penstemon tidestromii, Tidestroms beardtongue
- Penstemon tracyi, Trinity penstemon
- Penstemon triflorus, Hellers beardtongue
- Penstemon triphyllus, Riggins penstemon
- Penstemon tubiflorus, White wand beardtongue
- Penstemon tusharensis, Tushar Range beardtongue
- Penstemon uintahensis, Uinta Mountain beardtongue
- Penstemon unilateralis, Oneside penstemon
- Penstemon utahensis, Utah penstemon
- Penstemon variabilis
- Penstemon vaseyanus
- Penstemon venustus, Venus penstemon
- Penstemon virens, Front Range beardtongue
- Penstemon virgatus, Upright blue beardtongue
- Penstemon wardii, Wards beardtongue
- Penstemon washingtonensis, Washington beardtongue
- Penstemon watsonii, Watsons penstemon
- Penstemon whippleanus, Whipples penstemon
- Penstemon wilcoxii, Wilcoxs penstemon
- Penstemon wrightii, Wrights beardtongue
- Penstemon yampaensis, Yampa beardtongue
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