Phylogenetic re-examination of the genus Conocephalum Hill. (Marchantiales: Conocephalaceae)

Inter-relationship among the cryptic species in the genus Conocephalum Hill was studied using rbcL + rps4 sequences as well as morphological features. Samples used in this study originated from 1) the long-cultivated strains from Europe, North America, and Asia used for previous allozymes and molecular studies and 2) newly gathered plants mainly from Japan and Taiwan used for both molecular and morphological study. For the C. conicum/ salebrosum complex, a total of six species were confirmed, including a new species previously recognized as R type or Chemotype III (Toyota 1994, Kim et al. 2001 Miwa et al 2009). The R type has unique volatile component and morphological features; presence of Methyl cinnamate in natural conditions and absence of mucilage cavity in the central part of thallus. As for the C. japonicum complex, three cryptic species formerly recognized by allozymes and molecular analyses were confirmed. These three species are remotely distant from all the members of the C. conicum/ salebrosum complex. Conocephalum japonicum is here reinstated in the genus Sandea Lindb., as Sandea japonica Steph. ex Yoshin.