in E. Fenzl, Reise Novara, 181. 1870. 1870
Stem leaves spreading to squarrose, undulate-lunate when dry or moist, oblong-ligulate, 1.5–2(–3) mm; base strongly ovate-auriculate; costa 3/4 leaf length. Sexual condition autoicous or sometimes synoicous.
Phenology: Capsules mature winter–summer.
Habitat: Limestone rock, tree trunks, logs
Elevation: low elevations (0-70 m)
Fla., Mexico, West Indies, Central America, South America.
Neckeropsis undulata is easily recognized by the leaves that are lunate-undulate moist or dry, with a truncate apex and a broadly auriculate base. Outside the flora area, the species occurs from lowland to lower montane forests, from sea level to 1800 m.