Hypnaceae

Diagnosis: Plants mostly small and slender but elongate, or medium-sized, in often lustrous, soft, green to pale-green, thin mats. Stems creeping, irregularly to regularly pinnate, the branches complanate-foliate. Stem and branch leaves somewhat differentiated, ventral, dorsal and lateral stem leaves sometimes differentiated, when differentiated the ventral ones symmetric, oblong-ovate, with a wide insertion, gradually long-acuminate, the dorsal ones somewhat asymmetric, ovate, gradually acuminate, concave, the lateral ones strongly asymmetric, ovate-oblong, ± abruptly acuminate, concave; all stem leaves with margins subentire to distantly subserrulate throughout, plane to recurved; costa short and double; cells long-hexagonal to linear, smooth but with thickened cell end walls given the impression of prorulae; alar cells differentiated in extreme basal angles, 2-4 cells enlarged and inflated, ± oblong, sometimes colored, with a small group of subquadrate to short-rectangular cells directly above them, in lateral leaves the enlarged cells sometimes only on one side of the costa. Branch leaves with dorsal and lateral leaves sometimes differentiated, when so the dorsal ones erect-spreading, symmetric, lanceolate, gradually acuminate, the lateral ones wide-spreading, differentiated, asymmetric, oblong-ovate, gradually or ± abruptly acuminate, somewhat concave; all branch leaves with margins subentire to serrate throughout, the lateral leaves more strongly toothed, plane to narrowly recurved, especially above; costa short and double; cells linear to linear-flexuose, smooth, firm-walled, sometimes becoming shorter in the acumen; alar cells differentiated in extreme basal angles, colored, 2-4 cells enlarged with a small group of rhomboidal to subquadrate cells directly above them.