A revision of Plagiochila sect. Plagiochila in the neotropics

A taxonomic revision emphasizing characters of gametophytes as well as spor ophytes is presented for Plagiochila sect. Alternantes Carl and sect. Minut identes Carl. The two groups are treated as new synonyms of P. sect. Plagio chila. In the Neotropics, sect. Plagiochila contains two species, P. altern ans Lindenb. & Gottsche and P.,ovata Lindenb. & Gottsche, both widely distr ibuted at high elevations in tropical America. Ten species are reduced to s ynonymy and four are excluded from sect. Plagiochila. Lectotypes are design ated for Plagiochila alternans, P. ovata and for many of their synonyms. A preliminary evaluation of the relationships of P. sect. Plagiochila indicat es a close affinity to the neotropical Plagiochila subplana Lindenb. Plagio chila integerrima Steph. from Africa, previously placed in sect. Plagiochil a, is transferred to sect. Subplanae.