Leaf arrangements are invalid in the taxonomy of orchid species

PeerJ

article

Anna Jakubska-Busse¹  Elżbieta Żołubak¹  Zbigniew Łobas¹  Edyta Magdalena Gola² 

[1] Department of Botany, Institute of Environmental Biology, University of Wrocław;Department of Plant Developmental Biology, Institute of Experimental Biology, University of Wrocław

关键词: Epipactis;    Taxonomy;    Phyllotaxis;    Orchids;    Fibonacci pattern;   

DOI  :  10.7717/peerj.3609

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The selection and validation of proper distinguishing characters are of crucial importance in taxonomic revisions. The modern classifications of orchids utilize the molecular tools, but still the selection and identification of the material used in these studies is for the most part related to general species morphology. One of the vegetative characters quoted in orchid manuals is leaf arrangement. However, phyllotactic diversity and ontogenetic changeability have not been analysed in detail in reference to particular taxonomic groups. Therefore, we evaluated the usefulness of leaf arrangements in the taxonomy of the genus Epipactis Zinn, 1757. Typical leaf arrangements in shoots of this genus are described as distichous or spiral. However, in the course of field research and screening of herbarium materials, we indisputably disproved the presence of distichous phyllotaxis in the species Epipactis purpurata Sm. and confirmed the spiral Fibonacci pattern as the dominant leaf arrangement. In addition, detailed analyses revealed the presence of atypical decussate phyllotaxis in this species, as well as demonstrated the ontogenetic formation of pseudowhorls. These findings confirm ontogenetic variability and plasticity in E. purpurata. Our results are discussed in the context of their significance in delimitations of complex taxa within the genus Epipactis.

【 授权许可】

CC BY