Link to English Wikipedia entry: Sunset Crater Beardtongue
Link to German Wikipedia: Bartfaden
Link to French Wikipedia: Penstemon
Link to EOL.org: Penstemon clutei
Link to iNaturalist.org: Penstemon clutei
Binomial Links for Penstemon clutei on guenther-eichhorn.com
Dr. Günther Eichhorn Travel Website
Soaring website