| | Penstemon cyananthus Hook. | accepted | species | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus compactus (D. D. Keck) Neese | synonym of Penstemon compactus (D. D. Keck) Crosswh. | infraspecific name | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus longiflorus (Pennell) Neese | synonym of Penstemon longiflorus (Pennell) S. L. Clark | infraspecific name | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus subglaber (A. Gray) Pennell | synonym of Penstemon cyananthus var. subglaber (A. Gray) N. H. Holmgren | infraspecific name | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus subsp. compactus D. D. Keck | synonym of Penstemon compactus (D. D. Keck) Crosswh. | subspecies | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus subsp. longiflorus Pennell | synonym of Penstemon longiflorus (Pennell) S. L. Clark | subspecies | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus var. brandegeei Porter | synonym of Penstemon glaber var. brandegeei (Porter) C. C. Freeman | variety | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus var. judyae N. D. Atwood | accepted | variety | Plantae > ... > Plantaginaceae |
| | Penstemon cyananthus var. subglaber (A. Gray) N. H. Holmgren | accepted | variety | Plantae > ... > Plantaginaceae |
| | Penstemon glaber var. cyananthus (Hook.) A. Gray | synonym of Penstemon cyananthus Hook. | variety | Plantae > ... > Plantaginaceae |
| | Penstemon glaber f. cyananthus (Hook.) Voss | synonym of Penstemon cyananthus Hook. | form | Plantae > ... > Plantaginaceae |