Sporangia 2–3 (rarely 4), fused into synangia (Fig. 12), 2–6 mm in diam. or length, occurring in the axils of 2-lobed appendages. Sterile lateral appendages either minute and scale-like or leaf-like and 1–4 cm long. Stems simple or dichotomously branched. Rupestral or epiphytic plants Psilotaceae
Sterile lateral appendages 6–31 mm long; the apex mucronate. Synangia composed of 2 sporangia Tmesipteris
Apices of sterile lateral appendages truncate or bilobed. Synangia pointed or rounded. Aerial shoots 8.5–86 cm long including the stems. Spores 85–90 µm diam. Sterile lateral appendages not dilated to very much dilated at the base
Lower portions of the stems smooth except for the upper groove. Base of the sterile lateral appendages, mostly 3–9 mm broad; the upper side of the base much dilated and convex. Sterile lateral appendages light to yellow-green when dried. Synangia pointed. Widespread, usually in the mountains. RF, epiphytic on tree ferns Tmesipteris obliqua
Lower portions of the stems ridged on all sides. Base of the sterile lateral appendages 1–3 mm broad; the upper side of the base slightly dilated or not dilated. Sterile lateral appendages usually dark green when dried. Synangia pointed or more rarely rounded. Widespread. RF or sandstone gullies, on rocks or on trunks of Todea Tmesipteris truncata