Class: Ophioglossidae (Adder's-Tongues, Grape Ferns, Moonworts, Whisk Ferns)
The taxonomy presented here follows the World Flora Online's WFO Plant List as at mid-August 2026.
Order: Ophioglossales [1 family; 4 genera; 137 species]
Family: Ophioglossaceae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Botrychium subbifoliatum | (Brack.) Lyon (1905) | Makou | 1917 or 1935 or 1940 | Hawai'i, Kauai, Lanai, Maui, Molokai & Oahu, Hawaiian Islands, USA | Missing or Extinct | Access |
Order: Psilotales [1 family; 2 genera; 17 species]
Family: Psilotaceae
—No subordinate taxa