3. Pilosium (Brotherus) M. Fleischer, Musc. Buitenzorg. 4: 1158. 1923. • [Greek pilos, felted hairs, and -ion, diminutive, alluding to rhizoids].
Stereophyllum sect. Pilosium Brotherus in H. G. A. Engler and K. Prantl, Nat. Pflanzenfam. 227/228[I,3]: 899. 1907
Plants in dense mats, yellowish green, glossy. Stems with central strand absent; axillary hair apical cells 3. Stem and branch leaves differentiated, somewhat stiff, close, wide-spreading, somewhat curled when dry, curled downward when moist, dorsal leaves oblong-ovate, symmetric, not plicate; margins plane, entire to serrulate, especially distally; apex obtuse to short-acute; ecostate; laminal cell walls thin; medial and distal cells linear, smooth; lateral leaves oblong-lanceolate, cultriform, costa present, rarely to 1/3 leaf length. Perigonia with leaves ecostate. Perichaetia scattered along stems, often in pairs, leaves ovate to lanceolate, ecostate, laminal cells linear. Seta orange-red, straight. Capsule cernuous, orange-red, short-cylindric; exothecial cell walls collenchymatous; annulus undifferentiated; operculum short-rostrate; exostome teeth not shouldered, internal surface projecting; endostome papillose, basal membrane high, segments shorter than exostome teeth, cilia single, shorter than segments. Spores spheric, 7-9 µm.
Species 1: North Carolina, se Mexico, West Indies, Central America, n South America.