The following three similar Amanita spp. are described: Amanita djarilmari E.M.Davison, A. gardneri E.M.Davison from the south-west of Western Australia and A. millsii E.M.Davison & G.M.Gates (=A. sp. 10 ZLY-2014 HKAS 77322 in KUN) from Tasmania. All have a white- or pale-coloured pileus and white universal veil, but differ in the shape of the bulb, spore shape, and structure of the universal veil. All are from subgenus Lepidella section Phalloideae. Phylogenetic analysis showed that these species cannot be separated on the basis of data derived from nuclear ribosomal internal transcribed-spacer sequences. They can be separated in a multi-locus phylogeny of the 28S nuclear ribosomal large-subunit rRNA region, RNA polymerase-II region, β-tubulin region and translation elongation-factor 1-α region. Amanita djarilmari, A. gardneri, A. millsii and two other previously described species in section Phalloideae from southern Australia (A. eucalypti and A. marmorata) cluster in Clade IX. These, together with other species in this clade, segregate into two lineages, namely, Clade IX A, with a white or pale pileus, and Clade IX B, with a brown pileus. Solvent extraction, followed by liquid-chromatography tandem-mass spectrometry of A. djarilmari, A. eucalypti, A. gardneri and A. marmorata basidiomes did not detect the highly toxic amatoxins α-amanitin and β-amanitin, but did detect the phallotoxins phallacidin and phalloidin.