Leptodontium (Müll.Hal.) Lindb.

The following generic description is modified from Zander (1993).

Plants yellow- to orange-brown above, yellow to red-brown below, forming thick mats or short turves, on a wide range of substrates. Stems simple or branched, in cross-section rounded-pentagonal, central strand absent, sclerodermis present, hyaloderm often present (in N.Z. species). Leaves spreading to squarrose-recurved (in N.Z. species) when moist, erect to spreading, twisted to contorted when dry, ovate to long-lanceolate, occasionally lingulate or oblong, acute to acuminate; margins recurved in lower ⅓ to ¾, usually dentate in upper ⅕–½; upper laminal cells subquadrate, thin- to firm-walled, often thickened in corners, pluripapillose with simple or complex papillae, and with marginal cells occasionally forming a border; lower laminal cells usually strongly differentiated and often sharply demarcated, rectangular, walls thin or thick, occasionally porose (in N.Z. species). Costa excurrent, percurrent or failing (in N.Z. species), in cross-section with 2 stereid bands, which are exposed both adaxially and abaxially. Brood bodies in the form of clavate to obovate gemmae borne on short stalks in the leaf axils (in N.Z. species), or occasionally on leaf apices or leafless branchlets. Laminal KOH colour reaction usually yellow, less often orange.

Usually dioicous. Perichaetia terminal, with inner leaves usually long-lanceolate and convolute-sheathing. Perigonia terminal or lateral (not seen in N.Z. material). Setae short to elongate. Capsules cylindric to narrowly ovate. Operculum conic to conic-rostrate. Peristome of 16 linear teeth, occasionally rudimentary, basal cylinder absent or very low. Spores mostly c. 17–20 µm (smaller in N.Z. species), smooth or weakly papillose.

Essentially a high-elevation tropical genus. According to Zander (1993) it includes c. 40 species, although some authors (e.g., Magill 1981​​​​​​​, p. 189) suggest twice that number. A single species occurs in N.Z.

Leptodontium novae-seelandiae Müll.Hal., listed by Zander (1993​​​​​​​, p. 311) for N.Z. (as "Austr. 2"), is a nom. nud. based on a specimen from  "Greymouth" (Müller 1900​​​​​​​). Not seen.