## 3 Discussion  
Integrative taxonomy includes information from different types of data and methodologies; in the present study, molecular data aimed to establish a more robust species hypothesis and circumscription. Particularly for the genus _Lejeunea_, integration of molecular and morphological data should therefore be encouraged, because only such combined molecular-morphological studies allow for a reexamination of morphological characters that were previously considered to be of diagnostic importance in the species circumscriptions. Recent studies have demonstrated congruence or conflict between molecular and morphological data in _Lejeunea_, e.g., molecular phylogenetic analyses resolved three morphologically similar species, i.e., the African _Taxilejeunea pulchriflora_ [PERSON] and two Asian _L. propoguilifera_ [PERSON] and _L. tamasposii_ [PERSON]. [PERSON], in a robust monophyletic lineage [9]. In comparison, morphologically similar accessions initially assigned to _L. tumida_ [PERSON]. belong to four species nested in different clades [18]. Before molecular data, diagnostic characters such as toothed or eplicate perianths were used for generic distinction or subgenera delimitations. Such morphological data were often proved to be homoplastic in phylogenetic analyses [9; 19]. In the present study, one such morphological character is caducous leaves which were regarded as one characteristic for the species _L. cocoes_. In our phylogenetic analyses, however, we discovered two independent monophyletic lineages that by reexamination of the plant material turned out to be linked to the presence or absence of caducous leaves on specimens of the morpho-species of _L. cocoes_. We thus consider both clades as two different species and introduce the new species _L. malaysiana_ for the clade including plants with caducous leaves. Generally, vegetative reproduction of _Lejeunea_ is classified into five types, viz., plantlet regenerants, ribbon-like propagules, cladia, caducous, and fragmenting stem or branches [12; 20]. Regenerants and propagules that grow on leaf margins are very common forms of vegetative reproduction and have previously been described in _Lejeunea_[9; 20; 21; 22; 23; 24]. The cladia type thus far produces exclusively on _L. dimorpha_ T.Kodama, an obligate epiphyllous taxon reported from Vietnam, Peninsula Malaysia, Borneo, Papua New Guinea and the Philippines [25]. The caducous type may occur on the leaves, leaf lobes, underleaves, or branches, but caducous leaves is the most common and has been reported in many species of _Lejeunea_, e.g., in the Neotropics: _L. deplanata_ Nees, _L. phyllobloa_ Nees and Mont., _L. oligocluda_ Spruce, _L. perappillosa_ M.E.Reiner and K.C.Porto, _L. parviloba_ Angrstr., _L. flagellifera_ [PERSON] et al. ; in tropical America: _L. cochieta_ Spruce, _L. posimophylla_ C. Massal., _L. rionegrenis_ Spruce [20; 26]; in Africa: _L. kuerschneriana_ Pocs [27], and in tropical Asia: _L. subucuta_ Mitt. [28; 29]. The caducous leaves of the species mentioned above are occasionally with plantlet regenerants on the marginal leaf cells, e.g., [30] (p. 14), whereas in _L. malaysiana_, apart from the leaf margin, the plantlet regenerants are also seen growing on the top of long ribbon-like regenerants. Two different regenerants are developed on the caducous leaves of _L. malaysiana_: the young plantlets grow on top of the long ribbon-like regenerants (10-24(30) cells or 0.2-0.6 mm long and 4-5 cells wide) whereas other ribbon-like regenerants (4-6 cells long and 4-5 cells wide) developing on the marginal leaf cells and grow into young plantlets. Each caducous leaf of _L. malaysiana_ may produce 2(-6) regenerants and the leaf lobes produced on the stem are hardly found. However, the gynoecial shoot is usually is present with all its leaves.