Oxylobium/Gastrolobium (Fabaceae : Mirbelieae) conundrum: further studies using molecular data and a reappraisal of morphological characters

A molecular phylogeny of Oxylobium , Gastrolobium and related genera, including Brachysema , Jansonia , Nemcia and Podolobium, is presented. The study was conducted using five molecular regions and 48 taxa, utilizing chloroplast DNA (the trn K 5′ intron, psb A/ trn H intergenic spacer, trn L intron and adjacent trn L/ trn F intergenic spacer) and nuclear ribosomal DNA (ETS and ITS) markers. Oxylobium is shown to be polyphyletic, while Gastrolobium is paraphyletic, containing within it the genera Brachysema , Jansonia and Nemcia , as well as Oxylobium lineare . This concurs with a previous molecular analysis and the results of the two analyses are compared. Morphological traits, such as subtending bracts, ovule number and fluoroacetate content, are shown to be homoplastic and suites of characters for defining the different genera using different morphological characters are presented. Our results support a recent monograph that expands Gastrolobium to include Brachysema , Jansonia , Nemcia and Oxylobium lineare . This revision leaves Oxylobium and Podolobium occurring exclusively in eastern Australia, while Gastrolobium occurs almost exclusively in south‐western Australia, with only two species, G. brevipes and G. grandiflorum , occurring outside this area.