A Taxonomical Revision Of The Herbertus In China

The genus Herbertus S.F.Gray is a cosmopolitan genus of leafy liverworts,containing 41 species worldwide.Hengduan Mountains in China is a hot spot for the diversity of the genus.Because of relatively simple morphology and lack of stable taxonomically informative morphological characters,Herbertus is extremely difficult for classification only based on morphological characters.Therefore,a revision based on morphological observations and molecular phylogenetic analyses is extremely urgent.In present study,a taxonomical revision of Herbertus of China was carried out based on morphological and molecular phylogenetic analyses.More than 1600 specimens were checked,including 23 type specimens.Maximum likelihood,Maximum parisimony and Bayesian inference analyses of nuclear ribosomal internal transcribed spacer(nrITS)and chloroplast sequence(trnL-F,psbA)from 69 Herbertus accessions belonging to 22 species were adopted to study the relationship among species.The main results are shown below:1.Eleven species are recognized in China,including two species new to science:Herbertus neonorenus R.L.Zhu et P.F.Wang sp.nov.and Herbertus subfragilis R.L.Zhu et P.F.Wang sp.nov.Photographs of species and a key to species are provided.2.Two Herbertus species endemic to China,H.guangdongii and H.gaochienii are consolidated by molecular evidence.3.Herbertus aduncus,H.armitanus,H.huerlimannii,H.longifissus,H.parisii,and H.herpocladioides are excluded from the liverworts flora of China.4.Herbertus fragilis is resurrected from the synonym of H.aduncus,H.armitanus is resurrected from the synonym of H.sendtneri.5.Clarifying the species concept and distribution of H.dicranus and H.sendtneri.6.Seven morphology characters are considered to be useful for species discrimination among Herbertus through phylogenetic analyses: 1)structure of leaf lobe,2)arrangement of leaves in dry condition,3)length-width ratio of leaves,4)extent of bifidness of leaves,5)bifiding point of vitta,6)leaf cells papillose or not 7)numbers of branches.This is the first time to study the genus by morphological and molecular methods in China.The result will be scientific basis for the utilization and protection of biodiversity in China.Further more,accumulation of morphological and molecular data in this study will lay the foundation for the worldwide revision of this genus.