Schuster, T.M., Reveal, J.L., Bayly, M.J. & Kron, K.A. (2015), An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia. Taxon 64(6): 1204 [nom. nov.]

replaced synonym: Emex australis Steinh. legitimate

• Etymology: "Name from the Greek hypo (under) and Gaia (Earth) referring to the development of some underground fruits in this species."

Percy-Bower, J.M. & Parker, C.M. (16 March 2017), Updates to Western Australia’s vascular plant census for 2016. Nuytsia 28: 125 [secondary reference]

nomenclatural synonym: Emex australis Steinh. legitimate

CHAH (31 July 2018), Australian Plant Census: - APC [secondary reference]

nomenclatural synonym: Emex australis Steinh. legitimate taxonomic synonym: Emex centropodium Meisn. nom. illeg., nom. superfl.

• APC Dist.: WA (naturalised), NT (naturalised), SA (naturalised), Qld (naturalised), NSW (naturalised), NI (naturalised), Vic (naturalised), Tas (naturalised)

Bostock, P.D. & Holland, A.E. (August 2018), Appendix A: New names and name and status changes 2017 to 2018. Introduction to the Census of the Queensland Flora 2018: 11 [secondary reference]

nomenclatural synonym: Emex australis Steinh. legitimate

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