Orthodontium pellucens (Hook.) Bruch & Schimp ex C. Müll., Syn. Musc. Frond. 1: 240. 1849.
Bryum pellucens Hook., Icon. Pl. 1: 34. 1837. Apalodium pellucens (Hook.) Mitt., J. Linn. Soc., Bot. 12: 238. 1869. Protologue: “Columbia” [Ecuador]. In caves, Surrucucho, near Cuenca, Columbia. Prof. Jameson.
Plants small, yellowish green in tufts to 8 mm high; rhizoids moderately developed at base. Stem central strand present. Leaves 2–4 mm long, erect to erect-flexuose, twisted when dry, linear-lanceolate; apices acute to shortly acuminate; margins plane or weakly recurved below, not bordered, entire below, weakly serrulate above; costae percurrent, with stereid cells; upper cells linear-rhomboidal to linear‑fusiform, firm‑walled, 90–170 x 6–20 μm, basal cells reddish, enlarged, quadrate to oblong, thin-walled and bulging, alar cells not differentiated. Autoicous. Perigonia just below the perichaetia. Setae 5–17 mm long, yellowish. Capsules 1–3 mm long, oblong, oblong-cylindrical to sub-cylindrical, erect, furrowed to sulcate when dry, constricted at neck, bordered at mouth by 3–4 rows of oblate cells; opercula conic-rostrate, 0.75 mm long; peristome inserted within mouth, exostome yellow-orange, smooth, endostome nearly as long as the exostome teeth, yellow, smooth, basal membrane low, segments stout, not perforate or keeled, cilia absent. Spores 16–20 μm, densely papillose to warty. Calyptrae cucullate, 2 mm long.