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Phylogenetic analysis of the Neotropical genus Mezilaurus and reestablishment of Clinostemon (Lauraceae)
Author(s) -
Alves Flávio Macedo,
Souza Vinícius Castro
Publication year - 2013
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.12705/622.5
Subject(s) - monophyly , biology , sister group , genus , botany , phylogenetic tree , lauraceae , clade , zoology , evolutionary biology , genetics , gene
The delimitation of the genus Mezilaurus (Lauraceae) has always been controversial and depended on the weight given to some characters over others. This study is the first molecular phylogeny of Mezilaurus . It aims to test the monophyly of the genus and its relationships within the Mezilaurus group or other closely related genera. The Mezilaurus group had emerged as monophyletic in previous phylogenetic studies, and includes Anaueria, Chlorocardium, Mezilaurus, Sextonia , and Williamodendron . The phylogenetic analysis of Mezilaurus and related genera was based on trnH–psbA and ITS of ten species of Mezilaurus and thirteen outgroup species. Maximum parsimony and Bayesian inference were performed for each marker separately and for combined datasets. The combined analyses confirmed the monophyly of the Mezilaurus group, but did not support sister relationships of Anaueria and Chlorocardium . The Mezilauroids, containing Mezilaurus, Sextonia , and Williamodendron , formed a well–supported clade. However, the genus Mezilaurus , as currently defined, is not monophyletic and the Mezilaurus mahuba group ( Mezilaurus mahuba, M. triunca ) emerged as sister to Sextonia . Therefore, we suggest to remove the Mezilaurus mahuba group from Mezilaurus and re–establish it as Clinostemon. Mezilaurus and Clinostemon share rythmic branching with distally clustered leaves, bisexual flowers, three fertile stamens, representing the third androecial whorl, 2–locular anthers and a minute discoid cupule. Clinostemon , however, has stamens with downward recurved anthers and one pair of glands at the base of the filaments, while in Mezilaurus the anthers are erect and glands are absent.