Synonyms
Penstemon canescens f. brittoniorum (Pennell) Fernald
Penstemon canescens subsp. typicus Pennell
Penstemon canescens subsp. brittoniorum (Pennell) Pennell
Penstemon brittoniorum Pennell
Penstemon brittanorum Pennell ex Peattie
Penstemon canescens f. villicaulis Fernald