Tonguefern

This fern is native to the Hawaiian Islands but not endemic. The red arrow in this photo identifies a fertile blade which usually have different size and shape compared with the sterile blades. The adaxial surface is densely covered with scales while the abaxial surface is covered with sporangia. This fern is epiphytic in a wet forest south of Thurston Lava Tube at around 3700 ft/1128 m. These ferns can also be terrestrial or epipetric.

This fern is native to the Hawaiian Islands but not endemic. This photo shows the sporangia covered abaxial surface of a fertile blade. This fern is epiphytic in a wet forest south of Thurston Lava Tube at around 3700 ft/1128 m. These ferns can also be terrestrial or epipetric.

This fern is native to the Hawaiian Islands but not endemic. This photo shows the sporangia covered abaxial surface of a fertile blade. This fern is epiphytic in a wet forest south of Thurston Lava Tube at around 3700 ft/1128 m. These ferns can also be terrestrial or epipetric.

Endemic to Hawaiian islands. Leathery fronds and netlike veins. Epiphytic or terrestrial. The plant in this photo is epiphytic. Elevation 3830 ft (1168 m)

Endemic to Hawaiian Islands. This location is dense rain forest at around 2300 ft. (701 m)

Endemic to Hawaiian Islands. Growing on an Ohia tree (Metrosideros polymorpha). Elevation around 3830 ft. (1168 m)

Endemic to Hawaiian Islands. Growing on an Ohia tree (Metrosideros polymorpha). Elevation around 3830 ft. (1168 m)

Endemic to Hawaiian Islands. Note the fertile blade right side. Elevation around 3840 ft. (1171 m).

Endemic to Hawaiian Islands. Close up of sporangia on abaxial surface. Elevation around 3840 ft. (1171 m).

Endemic to Hawaiian Islands. Close up of sporangia on abaxial surface. Elevation around 3840 ft. (1171 m).

This fern is endemic to the Hawaiian Islands. Sighted occasionally in this wet rain forest of 240-250 inches/year. Elevation around 3200ft/976m

This fern is endemic to the Hawaiian Islands. Sighted occasionally in this wet rain forest of 240-250 inches/year. Elevation around 3200ft/976m. Note prominent veins.

This fern is endemic to the Hawaiian Islands. Sighted occasionally in this wet rain forest of 240-250 inches/year. Elevation around 3200ft/976m.

This fern is endemic to the Hawaiian Islands. Sighted occasionally in this wet rain forest of 240-250 inches/year. Elevation around 3200ft/976m. Note numerous sporangia on lower surface of this fertile blade.

This fern is endemic to the Hawaiian Islands. Elevation around 4150ft/1265m.

This fern is endemic to the Hawaiian Islands. Elevation around 4150ft/1265m. Note prominent veins.

Endemic to Hawaiian Islands. This photo shows the abaxial surface of a fertile frond. Elevation around 5800ft/1768m.

Endemic to Hawaiian Islands. Elevation around 5800ft/1768m.