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 0.5–2 mm long; the apex non-mucronate. Synangia composed of 3 (very rarely 2 or 4) sporangia (Fig. 12) Psilotum