Scholarlink

<p>The genus <i>Lejeunea</i>, including <i>Taxilejeunea</i>, is the largest genus within the family Lejeuneaceae and one of the most species-rich genera of liverworts. Due to extensive morphological homoplasy, molecular data are crucial for resolving its phylogeny and developing accurate species hypotheses. We analyzed sequences from two chloroplast regions (<i>trn</i>L-<i>trn</i>F, <i>rbc</i>L) and the nuclear ITS region, using around 500 accessions across 131 species globally. These analyses revealed complex species&#xa0;groups, such as the subcosmopolitan <i>L. flava</i> and the pantropical <i>L. adpressa</i>, as well as polyphyletic species&#xa0;groups, like the Neotropical <i>L. laetevirens</i> and the Paleotropical <i>L. papilionacea</i>. Expanding sampling is needed to address the taxonomy and variation of these species. Our study reveals both congruence and incongruence between morphological and molecular data in <i>Lejeunea</i>. While morphological differences do not always align with molecular evidence, there are cases where the two are congruent. These findings highlight the need for integrating molecular and morphological data to accurately define species boundaries and understand evolutionary relationships in <i>Lejeunea</i>. We describe and illustrate a new species from Fiji, <i>Lejeunea vitiensis</i>, based on both morphological characteristics and molecular phylogenetic analyses. This species is distinguished by its relatively large plants (&gt; 1.00&#xa0;mm wide), broadly rounded leaf apex, leaf cells with well-developed trigones and intermediate thickenings, roughed cuticle, large leaf lobules with an incurved free margin and a prominent rectangular disc cell below the first tooth, and an obovoid perianth with a beak 4–5 cells long. Detailed taxonomic descriptions of <i>L. vitiensis</i> and comparisons with its allied species&#xa0;are presented.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Species delimitation in Lejeunea (Lejeuneaceae, Marchantiophyta) through molecular phylogeny, morphology and biogeography, and a discovery of  a new species from Fiji

  • 期刊论文

  • 发表日期：

    2026年1月27日

查看全文
  • Gaik Ee Lee,
  • Julia Bechteler,
  • Tamás Pócs,
  • Alfons Schäfer-Verwimp,
  • Xiaolan He,
  • Claudine Ah-Peng,
  • Li Zhang

摘要

The genus Lejeunea, including Taxilejeunea, is the largest genus within the family Lejeuneaceae and one of the most species-rich genera of liverworts. Due to extensive morphological homoplasy, molecular data are crucial for resolving its phylogeny and developing accurate species hypotheses. We analyzed sequences from two chloroplast regions (trnL-trnF, rbcL) and the nuclear ITS region, using around 500 accessions across 131 species globally. These analyses revealed complex species groups, such as the subcosmopolitan L. flava and the pantropical L. adpressa, as well as polyphyletic species groups, like the Neotropical L. laetevirens and the Paleotropical L. papilionacea. Expanding sampling is needed to address the taxonomy and variation of these species. Our study reveals both congruence and incongruence between morphological and molecular data in Lejeunea. While morphological differences do not always align with molecular evidence, there are cases where the two are congruent. These findings highlight the need for integrating molecular and morphological data to accurately define species boundaries and understand evolutionary relationships in Lejeunea. We describe and illustrate a new species from Fiji, Lejeunea vitiensis, based on both morphological characteristics and molecular phylogenetic analyses. This species is distinguished by its relatively large plants (> 1.00 mm wide), broadly rounded leaf apex, leaf cells with well-developed trigones and intermediate thickenings, roughed cuticle, large leaf lobules with an incurved free margin and a prominent rectangular disc cell below the first tooth, and an obovoid perianth with a beak 4–5 cells long. Detailed taxonomic descriptions of L. vitiensis and comparisons with its allied species are presented.