s United States, Mexico, West Indies, Central America, South America, Asia, Africa, Pacific Islands, Australia.
Genera 8, species ca. 28 (3 genera, 3 species in the flora).
There are two subfamilies recognized for Stereophyllaceae. Plants of subfam. Stereophylloideae M. Fleischer have similar stem and branch leaves; strong costae to 1/3–3/4 leaf length on all leaves; cernuous or erect capsules; exothecial cells not or scarcely collenchymatous; and spores 9–27 µm. Plants of subfam. Pilosioideae W. R. Buck & Ireland have differentiated stem and branch leaves; weak costae, rarely to 1/3 leaf length, only on lateral leaves; cernuous capsules; exothecial cells collenchymatous; and spores 7–9 µm.
|1||Stem and branch leaves differentiated; costae rarely to 1/3 leaf length, only on lateral leaves; capsules cernuous; exothecial cell walls collenchymatous; spores 7-9 µm.||Pilosium|
|1||Stem and branch leaves similar; costae 1/3 -3/4 leaf length, on all leaves; capsules cernuous or erect; exothecial cell walls thin; spores 12-27 µm||> 2|
|2||Leaf apices abruptly acute to obtuse; distal laminal cells quadrate to rhomboidal, 1-papillose over lumina or sometimes smooth.||Stereophyllum|
|2||Leaf apices acuminate, rarely acute or obtuse; distal laminal cells broadly fusiform, smooth or occasionally prorulose on abaxial surface.||Entodontopsis|