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Issue: Vol. 776 No. 3: 25 Sept. 2026
Type: Article
Published: 2026-09-25
DOI: 10.11646/phytotaxa.776.3.6
Page range: 294-300
Abstract views: 16
PDF downloaded: 0

Taxonomic reassessment of Fissidens acacioides Schrad. (Fissidentaceae): synonymization of its varieties

Universidade de Brasília; Departamento de Botânica; Campus Darcy Ribeiro; Asa Norte; 70.910-900 - Brasília; DF (Brazil)
Universidade de Brasília; Departamento de Botânica; Campus Darcy Ribeiro; Asa Norte; 70.910-900 - Brasília; DF (Brazil)
IPA; Instituto de Pesquisas Ambientais; Av. Miguel Estefno 3687; 40301-902 - São Paulo; SP (Brazil)
Universidade Estadual do Rio Grande do Sul; Unidade Litoral Norte-Osório; Rua Machado de Assis; 95.520-000 - Osório; Rio Grande do Sul; RS (Brazil)
Universidade de Brasília; Departamento de Botânica; Campus Darcy Ribeiro; Asa Norte; 70.910-900 - Brasília; DF (Brazil)
Bryophytes integrative taxonomy morphological variation molecular phylogeny species delimitation

Abstract

Fissidens acacioides Schrad. exhibits extensive morphological variation, which has led to the recognition of three varieties: F. acacioides var. acacioides, F. acacioides var. immersus, and F. acacioides var. brevicostatus. In this study, we reassess the taxonomic delimitation of these varieties using an integrative approach combining morphological and molecular data. We examined 80 specimens from eight herbaria, and molecular analyses were based on the plastid markers rps4 and trnG. The morphological characters traditionally used to distinguish the varieties, including costa length, leaf shape, gametophyte size, and capsule position, showed substantial overlap and lacked consistent diagnostic differences. Molecular analyses recovered F. acacioides var. acacioides and F. acacioides var. immersus in a strongly supported clade, with no genetic divergence between them. Examination of the type material of F. acacioides var. brevicostatus likewise revealed no diagnostic characters supporting its recognition as a distinct taxon. Based on the congruence between morphological and molecular evidence, we propose treating all three varieties as conspecific and synonymizing F. acacioides var. immersus and F. acacioides var. brevicostatus under F. acacioides var. acacioides.

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How to Cite

Alkimim-Faria, A.L., Teixeira, T.P.D.O., Peralta, D.F., Bordin, J. & Carvalho-Silva, M. (2026) Taxonomic reassessment of Fissidens acacioides Schrad. (Fissidentaceae): synonymization of its varieties. Phytotaxa 776 (3): 294–300. https://doi.org/10.11646/phytotaxa.776.3.6