2001 Volume 90 Pages 221-240
Circumscription of the family Sematophyllaceae is controversial, and taxonomic position of the genera Brotherella, Trismegistia, Wijkia and its allies has been repeatedly discussed and is still fluctuating. A phylogenetic study was carried out to investigate the phylogenetic position of the genera Brotherella, Trismegistia, Wijkia and their allies inferred from the chloroplast ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene data. The relationships between 40 species representing the Sematophyllaceae and related taxa are evaluated based on the rbcL data set using the following methods: neighbor-joining (NJ), minimum-evolution (ME), maximum-parsimony (MP) and maximum-likelihood (ML) methods. The results of the present study suggest that (1) the family Sematophyllaceae (s. lat.) are monophyletic; (2) the genera Wijkia, Trismegistia and Acanthorrhynchium do not form a single clade; and (3) the genera Brotherella, Pylaisiadelpha, Heterophyllium, Isocladiella, and some species treated as members of the Hypnaceae, such as Hypnum tristo-viride or Isopterygium tenerum should be placed in the Sematophyllaceae (s. lat.). Our research shows that the Sematophyllaceae (sensu Hedenäs & Buck 1999) are not monophyletic. Since the monophyly of the Sematophyllaceae (s. lat.) including Brotherella and its allies is well supported, we propose here that we could treat the family in a wider sense. Furthermore, the present study suggests that Entodontaceae (s. str.) are resolved as a monophyletic group, and should be placed in a clade sister to the Sematophyllaceae (s. lat.). The results show the necessity to reconsider the familial circumscription of the Sematophyllaceae and the Hypnaceae.