These are the lycophytes, ferns and fern allies that are officially listed as rare by the State of Pennsylvania. The information is taken from the Pennsylvania Biological Survey Vascular Plants Technical Committee Page..
True Ferns | ||
| Asplenium bradleyi | Bradley's spleenwort | E |
| Asplenium pinnatifidum | lobed spleenwort | R |
| Asplenium resiliens | black-stalked spleenwort | E |
| Cryptogramma stelleri | slender rock-brake | E |
| Cyrstopteris lauentiana | Laurential bladder fern | E |
| Lygodium palmatum | Hartford fern | R |
| Dryopteris campyloptera | mountain wood fern | E |
| Dryopteris celsa | log fern | E |
| Gymnocarpium appalachianum | Appalachian oak fern | E |
| Polystichum braunii | Braun's holly fern | E |
| Gymnocarpium heterosporum | oak fern | X |
Fern Allies | ||
| Ophioglossum engelmannii | limestone adder's-tongue | E |
| Ophioglossum pycnostichum | southeastern adder's-tongue | X |
| Equisetum variegatum | variegated horsetail | E |
| Equisetum ferrissii | scouring rush | E |
Lycophytes | ||
| Huperzia porophila | rock clubmoss | E |
| Huperzia selago | mountain clubmoss | X |
| Lycopodiella alopecuroides | foxtail clubmoss | E |
| Diphasiastum sabinifolium | fir clubmoss | X |