Perkins, A.J. (14 December 2018), Hydrocotyle eichleri, H. papilionella and H. tuberculata (Araliaceae), three new annual species from Western Australia. Nuytsia 29: 238-240, Figs 3 (map), 4 [tax. nov.]

• Type: "south-east of Coorow, Western Australia [precise locality withheld for conservation reasons], 26 September 1999, M.N. Lyons & S.D. Lyons 4891 (holo: PERTH 08933510; iso: MEL)."

taxonomic synonym: Hydrocotyle sp. Vigintimilia (P.G.Wilson 7940) WA Herbarium [n/a] taxonomic synonym: Hydrocotyle vigintimilia H.Eichler manuscript name common name: Butterfly Pennywort [n/a]

• Etymology: "The epithet is derived from the Latin ‘papilio’ (genitive papilionis) and means ‘a small butterfly’, which is a reference to the lateral profile of the fruit ..."

Parker, C.M. & Percy-Bower, J.M. (10 December 2019), Updates to Western Australia’s vascular plant census for 2019. Nuytsia 30: 346 [secondary reference]

taxonomic synonym: Hydrocotyle sp. Vigintimilia (P.G.Wilson 7940) WA Herbarium [n/a]

Council of Heads of Australasian Herbaria (7 July 2021), Australian Plant Census: - APC [secondary reference]

taxonomic synonym: Hydrocotyle sp. 3 (Esperance-Ravensthorpe) [n/a] taxonomic synonym: Hydrocotyle sp. 3 (Esperance-Ravensthorpe; Hj.Eichler 20000) [n/a] taxonomic synonym: Hydrocotyle sp. Vigintimilia (P.G.Wilson 7940) WA Herbarium [n/a] taxonomic synonym: Hydrocotyle vigintimilia H.Eichler manuscript name

• APC Dist.: WA

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