Taxonomic revision of Australian <i>Erythrophleum</i> (Fabaceae: Caesalpinioideae) including description of two new species

Abstract

The genus Erythrophleum Afzel ex R.Br. is revised for Australia and three species are recognised, all previously included in E. chlorostachys (F.Muell.) Baill. Erythrophleum arenarium R.L.Barrett & M.D.Barrett is described as a new species to accommodate populations from desert sands of the Great Sandy Desert and Dampier Botanical Districts in north-western Australia, parapatric to the remaining species. Erythrophleum pubescens R.L.Barrett & M.D.Barrett is described as a new species spanning tropical Australia, and is sympatric with E. chlorostachys sensu stricto in the Northern Territory and adjacent areas of Western Australia and Queensland. Morphological examination has shown these three taxa to be consistently distinct across their respective ranges. Analyses of the nuclear ribosomal ITS1 region recovered three well-supported clades corresponding to the three morphologically defined species, and ITS1 has utility as a marker to separate sterile specimens. Erythrophleum pubescens is widespread in the Australian Monsoon Tropics, from the coast of Western Australia, near Derby, to Cape York Peninsula in northern Queensland. Erythrophleum chlorostachys is also widespread, from the eastern Kimberley Region, in Western Australia, to the Gulf of Carpentaria, in northern Queensland. A lectotype is chosen for Laboucheria chlorostachya F.Muell. Full descriptions, illustrations of key features and identification keys are provided for the three Australian species. A summary of the significant utilisation of Erythrophleum species is presented.