Morphological phylogeny of Tradescantia L. (Commelinaceae) sheds light on a new infrageneric classification for the genus and novelties on the systematics of subtribe Tradescantiinae

Abstract

Throughout the years, three infrageneric classifications were proposed for Tradescantia along with several informal groups and species complexes. The current infrageneric classification accepts 12 sections – with T. sect. Tradescantia being further divided into four series – and assimilates many concepts adopted by previous authors. Recent molecular-based phylogenetic studies indicate that the currently accepted sections might not represent monophyletic groups within Tradescantia. Based on newly gathered morphological data on the group, complemented with available micromorphological, cytological and phytochemical data, I present the first morphology-based evolutionary hypothesis for Tradescantia. Furthermore, I reduce subtribe Thyrsantheminae to a synonym of subtribe Tradescantiinae, and propose a new infrageneric classification for Tradescantia, based on the total evidence of the present morphological phylogeny, in accordance to the previously published molecular data.

Total evidence phylogeny of Pontederiaceae (Commelinales) sheds light on the necessity of its recircumscription and synopsis of Pontederia L.

“…observ. ), with Tradescantiazanonia (L.) Sw. (Commelinaceae) being an exception (Pellegrini 2017b; Pellegrini and Faden 2017). In Pontederiaceae, the anthocarp seems to be related to hydrochoric dispersion, which is also supported by the remaining synapomorphies for the family (i.e.…”

“…anatomy, ecology, geography, palynology, micromorphology, phytochemistry etc. ; Pellegrini 2017b). Furthermore, without the inclusion of morphological characters in a phylogenetic analysis, there is no way to obtain morphological synapomorphies to support the recovered relationships and any proposed new classification (Lipscomb et al 2003; Wiens 2004; Assis and Rieppel 2011).…”

WITHDRAWN: Wandering throughout South America: Taxonomic revision of Tradescantia subg. Austrotradescantia (D.R.Hunt) M.Pell. (Commelinaceae)

“… Tradescantia , is the second largest genus in the family, with ca. 90 species ( Pellegrini 2017 ). It is characterised by its actinomorphic flowers with six equal to subequal stamens, seeds with linear hilum and main florescences composed by a double-cincinni fused back to back, with each cincinni subtended by a frondose bract ( Faden 1998 ; Panigo et al 2011 ; Pellegrini 2017 ).…”

“…90 species ( Pellegrini 2017 ). It is characterised by its actinomorphic flowers with six equal to subequal stamens, seeds with linear hilum and main florescences composed by a double-cincinni fused back to back, with each cincinni subtended by a frondose bract ( Faden 1998 ; Panigo et al 2011 ; Pellegrini 2017 ). Throughout the years, four infrageneric classifications were proposed for Tradescantia : Clarke (1881) , Brückner (1930) , Hunt (1975 , 1980 , 1986 ) and Pellegrini (2017) .…”

“…It is characterised by its actinomorphic flowers with six equal to subequal stamens, seeds with linear hilum and main florescences composed by a double-cincinni fused back to back, with each cincinni subtended by a frondose bract ( Faden 1998 ; Panigo et al 2011 ; Pellegrini 2017 ). Throughout the years, four infrageneric classifications were proposed for Tradescantia : Clarke (1881) , Brückner (1930) , Hunt (1975 , 1980 , 1986 ) and Pellegrini (2017) . The current classification divides Tradescantia into five monophyletic subgenera ( Hertweck and Pires 2014 ; Pellegrini 2017 ), further supported by micro- and macromorphological characters, anatomy, phytochemistry and cytology ( Pellegrini 2017 ).…”