A Taxonomic Revision of the Family Stephaniellaceae (Marchantiophyta).

Stephaniellaceae (R.M. Schust.) R.M. Schust. is a small family that occurs in the high elevations of the Americas, from Mexico to northern South America and South Africa. This taxonomic revision is based on the examination of herbarium specimens from various parts of its range, and field work in Mexican localities. The taxonomic treatment provides a re-description and illustration of the family, its genera and species, and a taxonomic key based on gametophytic characters. Five species in two genera ( Stephaniella and Stephaniellidium) are recognized. Stephaniella is characterized by hyaline leaves, abundant paraphyllia, and sporophyte developed within the perianth. Stephaniellidium is characterized by chlorophyllose leaves, scarce paraphyllia, and sporophyte developed within a marsupium. [ABSTRACT FROM AUTHOR]