Zone 4: Fern
Click on plant photo for specific plant information.
 | Adiantum capillus-veneris | 'Iwa'iwa, 'iwa'iwa hāwai, 'iwa'iwa kahakaha, Venus' hair fern, maidenhair fern | I | 1 TO 2 | 1 | |
| 
| Asplenium nidus | 'Ēkaha, 'Ēkaha kuahiwi, 'Ēkahakaha, bird's nest fern | I | 4 TO 6 | 6 | |
| 
| Cyclosorus interruptus | Neke, swamp cyclosorus | I | 2 | 8 | |
| 
| Dicranopteris linearis f. emarginata | Uluhe, unuhe, false staghorn | E | 4 TO 8 | 38 | |
| 
| Dicranopteris linearis f. linearis | Uluhe, unuhe, false staghorn | I | 4 TO 8 | 38 | |
| 
| Haplopteris elongata | 'Ohe'ohe, mana | I | <1 TO 2 | 2 | |
| 
| Lepisorus thunbergianus | Pākahakaha, 'Ēkaha, 'ākōlea, pua'a | I | 1 TO 2 | 1 | |
| 
| Nephrolepis exaltata spp. Hawaiensis | Ni'ani'au, 'ōkupukupu, pāmoho, kupukupu, palapalai, sword fern | E | 1 TO 4 | 8 | |
| 
| Ophioderma pendulum ssp. falcatum | Puapua moa, laukahi, adder's tongue | I | 1 TO 2 | 1 | |
| (No photo) | Ophioglossum nudicaule | Adder's tongue | I | <1 | 2 | |
| (No photo) | Ophioglossum petiolatum | Adder's tongue | 1 | <1 | 2 | |
| 
| Pneumatopteris hudsoniana | Laukahi | E | 4 TO 6 | 4 | |
| 
| Psilotum nudum | Moa, moa nahele, pipi, 'o'omoa, upright whiskfern | I | <1 TO 2 | 2 | |
| 
| Sadleria cyatheoides | 'Ama'u, ma'u, ma'uma'u, pua'a 'ehu'ehu, 'ama'uma'u | E | 6 TO 13 | 10 | |
| 
| Sphenomeris chinensis | Pala'ā, palapala'ā, pā'u o Pala'e, pala'e, lace fern | I | 1 TO 3 | 2 | |
| (No photo) | Vandenboschia draytoniana | N/A | E | 1 TO 2 | 1 | |
E* - Endangered