2004 Volume 95 Pages 207-217
A most striking feature of cloud forests is the pendent epiphytic bryophyte communities. Of those, the majority are pleurocarpous moss species, chiefly of the Meteoriaceae, a family mainly occurring in the Southern Hemisphere. The pendent life-form was regarded as a prominent character uniting this family. Recent molecular and morphological investigations challenge this concept, as other clear morphological characters for the family are missing. We analysed a selected set of species, representing the major pendent genera and their relatives. Molecular analyses of the psbT-H and the trnL-F regions of the chloroplast DNA (cpDNA), together with ITS2 sequence data of the nuclear ribosomal transcription unit (nrDNA), reveal that the pendent life form has evolved independently in several moss lineages, as epiphytism and the pendent life form are presumed to be derived characters. The congruent trees based on either cpDNA or nrDNA, as well as the combined data set, resolve the investigated pendent species mostly as members of the Brachytheciaceae, Meteoriaceae, and Lembophyllaceae. An improved understanding of the morphological characters will provide new definitions of these families. Characters which have been earlier used to delimit the Meteoriaceae, such as the upright capsule, or papillose leaf cells are suggested as adaptations for an epiphytic life and are therefore not useful in taxonomic classification. This emphasises the need to reevaluate the morphological circumscription of the respective families, especially with regard to the Meteoriaceae.