Phylogeny of the restiid clade (Poales) and implications for the classification of Anarthriaceae, Centrolepidaceae and Australian Restionaceae

Abstract

Abstract Three families, Anarthriaceae, Restionaceae and Centrolepidaceae, are generally recognised in the restiid clade of Poales. A new phylogeny is presented, with fuller sampling of Australian taxa, based on analyses of trnL‐F , trnK and rbcL data from the chloroplast genome. The findings agree with the major groups shown in previous molecular studies but provide a more substantial basis for reviewing the classification at family and generic levels. Anarthriaceae is sister to Restionaceae, with Anarthria sister to Lyginia + Hopkinsia . Centrolepidaceae, on an extremely long branch, appears embedded in Restionaceae in Bayesian trees; although it appears as sister to Restionaceae in analyses that are more subject to long‐branch attraction (in parsimony analyses and those of data from the less‐conserved trnL‐F cpDNA region). Accepting the embedded position, which would make this a subfamily of Restionaceae, the basal division in the Restionaceae separates the African subfamily Restionoideae from the Australasian clade (Sporadanthoideae, Centrolepidoideae, Leptocarpoideae). In subfamily Leptocarpoideae, Eurychorda forms the basal branch. At the next dichotomy the Leptocarpus clade, together with the Winifredia clade, is separated from a diverse assemblage including Loxocarya , Chordifex , Baloskion , Desmocladus , Lepidobolus and allied genera. The phylogeny indicates that several currently recognised genera are not monophyletic and that changes to the generic classification are required. A matrix of morphological characters was prepared and these were mapped onto the Bayesian consensus DNA tree to identify synapomorphies of the clades and genera. Observations on leaf laminae indicate that fully or partially unifacial leaf laminae are a synapomorphy of the restiid clade. The morphological characterisation of the following are considered: the restiid clade, Anarthriaceae, Restionaceae enlarged to include subfamily Centrolepidoideae, Leptocarpus s.l. (including as potential synonyms Meeboldina and Stenotalis ) and Desmocladus s.l. (including potentially Harperia , Onychosepalum and Kulinia ).

Keywords

Affiliated Institutions

• Royal Botanic Garden Sydney AU

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