Genera 4, species 32 (3 genera, 6 species in the flora).
The leaves of Hedwigiaceae are absolutely ecostate, strongly concave, decurrent-auriculate, and acute to abruptly acuminate, often with striking white apices or piliferous with long, pellucid apical hair-points. Laminal cells throughout the family are mostly subquadrate and arranged in longitudinal lines throughout the leaf, thick-walled, papillose, and collenchymatous, with patches of elongate cells in the leaf middle near the insertion, an area that is also usually more brightly colored than the rest of the leaf. Without peristomes, the family is difficult to place, but B. H. Allen (2002) gave a good synopsis of the speculative relationships. The family in the past has been placed among the pleurocarpous mosses because the leaves are ecostate, a trait rare among acrocarpous arthrodontous mosses (B. Goffinet and W. R. Buck 2004). However, the habit is acrocarpous, and the branching is sympodial (E. DeLuna, unpubl.) despite the plagiotropous habit typical of pleurocarpous mosses. All capsules have lax, flaccid cells in the neck region. When dry, the cells collapse making the capsule irregularly and variously pleated at the base; when moist, they are swollen, rendering the capsule urceolate, strongly fusiform or turbinate when dry, and globose, broadly oblong, cylindric-elliptic, or pyriform when moist. The fourth genus in the family, Hedwigidium Bruch & Schimper with two species is known from Old and New World tropics and temperate areas.
|1||Capsules immersed, turbinate-urceolate, subglobose, short-ovoid, or obovoid, mouth wide; operculum planoconvex, sometimes subumbonate-apiculate; medial laminal cell papillae simple or multifid; stoloniform branches absent; perichaetial leaf margins ciliate (entire in H. detonsa); calyptrae 0.5-0.9 mm, pilose or naked; capsule stomata cryptoporic.||Hedwigia|
|1||Capsules exserted, cylindric-fusiform, ellipsoid, ovate, turbinate, or pyriform, mouth wide or narrow; operculum conic, rostrate; medial laminal cell papillae simple; stoloniform branches present or absent; perichaetial leaf margins entire; calyptrae 2-4 mm, naked; capsule stomata phaneroporic||> 2|
|2||Leaf apices concolorous, acute to abruptly short-acuminate, sometimes apiculate in larger leaves; medial laminal cells 3-4(-6)-papillose, papillae low, irregularly rounded; capsules cylindric-fusiform when dry, (1.9-)2-2.2 mm; operculum medium- to long-rostrate; leaves plicate when dry; stoloniform branches present; spores finely, evenly papillose.||Braunia|
|2||Leaf apices opaque to translucent white, acute, ± gradually acuminate, or piliferous; medial laminal cells 1 (or 2)-papillose, papillae stoutly tuberculate; capsules obpyriform to turbinate when dry, 1-1.3 mm; operculum short-rostrate; leaves not plicate; stoloniform branches absent; spores finely to coarsely vermiculate-papillose.||Pseudobraunia|