Fissidens angustifolius Sullivant 1861

Fissidens angustifolius is easily distinguished from other species of sect. Fissidens, which has limbate leaves, by its unipapillose laminal cells.

Plants small, dark green. Leafy stems usually simple, 2–3 mm long, 1.3–1.6 mm wide; cortical stem cells small, thick-walled; axillary hyaline nodules not differentiated; central strand not differentiated. Leaves in 4–5 pairs, more or less densely foliated; upper leaves much larger than lower leaves, narrowly lanceolate to lanceolate, 1.1–1.9 mm × 0.24–0.36 mm, acute at the apex, base of dorsal laminae wedge-shaped, not decurrent; margins of apical laminae weakly serrulate by projecting cells; vaginant laminae about 1/2 the leaf length; costa of upper leaves percurrent; cells at apical laminae quadrate to hexagonal, each with a small papilla, 6.5–10.3 µm long, thin-walled; limbidia throughout leaf margins, composed of 3 rows of hyaline, elongate, smooth cells on the vaginant laminae, 1–2 rows on the apical laminae. Rhizoautoicous. Male stems at base of female stems, short; antheridia terminal. Archegonia terminal. Setae 2.0–2.8 mm long, smooth; capsules cylindrical, symmetrical; urn 0.30–0.51 mm long; peristome teeth 0.14–0.16 mm long, 32–36 µm wide at base, spirally thickened above, with large scattered papillae at middle, minutely and densely papillose below; exothecial cells quadrate, thin-walled, collenchymatous; opercula rostrate, 0.40–0.53 mm long. Calyptrae campanulate, 0.53–0.59 mm long, covering opercula. Spores 12.9–17.4 µm in diameter.

Distribution: China, Fiji, Samoa, New Caledonia, throughout the Americas.

Habitat: on soil; 600 m alt.

Fissidens dixonianus Bartr., Bishop Mus. Occas. Pap. 19(11): 220. 1948. Fissidens diversiretis Dix., Proc. Linn. Soc. New South Wales 55: 270. 1930, hom. illeg.