Fissidens allionii Broth., Rev. Bryol. 47: 5. 1920.

Type. Ecuador, Allioni, Bryotheca E. Levier 8291 (H).

Plants 4.0–5.55 mm × 1.5–1.75 mm. Leaves to 1.5 mm × 0.15–0.18 mm; apex acute; margins serrulate to more or less entire; vaginant laminae more or less 1/2 the leaf length, unequal; minor laminae acute; costa very strong, (31–)36–50(–54) µm broad, occupying ½ or more the width of the leaves, excurrent; cells 6–9 µm in diameter, more or less sharply mammillose-papillose, bistratose in places. Sporophytes terminal on short axillary branches.