SUGGESTIONS FOR THE DELIMITATION OF THE LEUCODONTACEAE AND THE INFRAGENERIC CLASSIFICATION OF THE GENUS LEUCODON

抄録

  Deficiency of morphological data for phyletic analyses is discussed, with special reference to the delimitation of the Leucodontaceae and the interspecific relationships within the genus Leucodon. Since all genera of the Leucodontaceae are epiphytes, some of morphological features that are usually regarded to indicate common descendant might be caused by mere adaptation to the epiphytic niche. Moreover, since most genera of the family are monotypic and remotely related to each other, it seems nearly impossible to infer the phyletic relationship within the family on the basis of morphological data sets. It is also supported by the discordance between morphological and genetic (i.e., allozyme) data sets in reconstructing phyletic relations within Leucodon. Though morphology still has much importance in species taxonomy, non-morphological data, especially molecular ones are inevitable for sound progress of phylogenetic systematics.