XVI International Botanical Congess
The thalloid liverwort complex, Conocephalum conicum (L.) Dum., consists of six known, genetically highly differentiated but morphologically cryptic taxa that probably merit species rank. Currently, they can be identified only on the basis of diagnostic isozyme markers. Based on a worldwide sample of plants and the published data, an isozyme-based taxonomic key" has been constructed and used to clarify identity of some recently described taxa from Japan (Odrzykoski and Akiyama, unp.). This key may also be useful to identify samples for taxonomic studies whose goal is to find morphological, diagnostic characters. Recent studies on sequence differentiation of 5' flanking region and coding sequence of psbA gene in these cryptic species (Kim et al., unp.) have opened the way for using PCR-based DNA markers, which may prove useful in identifying herbarium specimens (including the type). This should help to integrate studies of genetic differentiation with classical taxonomy.