These are the lycophytes, ferns and fern allies that are officially listed as rare by the State of Maryland. The information is taken from the Maryland Department of Natural Resources' Rare, Threatened, and Endangered Plants of Maryland List..
True Ferns | |||||
| Asplenium bradleyi | Bradley's Spleenwort | G4 | SH | X | |
| Asplenium pinnatifidum | Lobed Spleenwort | G4 | S1 | E | |
| Asplenium resiliens | Black-stem Spleenwort | G5 | S1 | E | |
| Asplenium ruta-muraria | Wall-rue | G5 | S3 | ||
| Cystopteris bulbifera | Bulblet Fern | G5 | S3 | ||
| Cystopteris tennesseensis | Tennessee Bladder-fern | G5 | S1 | ||
| Diplazium pycnocarpon | Glade Fern | G5 | S2 | T | |
| Dryopteris campyloptera | Mountain Wood-fern | G5 | S1 | E | |
| Dryopteris celsa | Log Fern | G4 | S3 | ||
| Dryopteris clintoniana | Clinton's Wood-fern | G5 | S1 | E | |
| Dryopteris goldiana | Goldie's Wood fern | G4 | S | ||
| Gymnocarpium dryopteris | Oak Fern | G5 | S1 | E | |
| Lygodium palmatum | Climbing Fern | G4 | S2 | T | |
| Matteuccia struthiopteris | Ostrich Fern | G5 | S2 | ||
| Pellaea glabella | Smooth Cliffbrake | G5 | S1 | E | |
| Phegopteris connectilis | Northern Beech Fern | G5 | S2 | ||
| Pleopeltis polypodioides | Resurrection Fern | G5 | S3 | ||
| Thelypteris simulata | Bog Fern | G4G5 | S2 | T | |
| Woodsia ilvensis | Rusty Woodsia | G5 | S1 | T | |
Fern Allies | |||||
| Equisetum fluviatile | Water Horsetail | G5 | S1 | E | |
| Equisetum sylvaticum | Wood Horsetail | G5 | S1 | E | |
| Botrychium lanceolatum var. angustisegmentum | Triangle Grape-fern | G5 | SH | X | |
| Botrychium matricariifolium | Matricary Grape-fern | G5 | SU | ||
| Botrychium multifidum | Leathery Grape-fern | G5 | SH | X | |
| Botrychium oneidense | Blunt-lobe Grape-fern | G4Q | S1 | E | |
| Botrychium simplex | Small Grape-fern | G5 | SH | X | |
Lycophytes | |||||
| Huperzia porophila | Rock Clubmoss | G4 | SX | ||
| Isoetes engelmannii | Appalachian Quillwort | G4 | S3 | ||
| Isoetes riparia | Riverbank Quillwort | G5? | SU | ||
| Lycopodiella caroliniana | Carolina Clubmoss | G5 | S1 | E | |
| Lycopodiella inundata | Bog Clubmoss | G5 | S2 | ||
| Lycopodium tristachyum | Ground-cedar | G5 | S3 | ||