"Ophioglossaceae" . . . "Ophioglossales" . . . . . . "Ophioglossum engelmannii" . "Plantae" . . . "Ophioglossum" . . "Limestone Adderstongue" . "Streptophyta" . "Ophioglossopsida" . "Prantl" . . . "Ophioglossum engelmannii Prantl" . . . .