Johnson, L.A.S. (1959), The families of cycads and the Zamiaceae of Australia. Proceedings of the Linnean Society of New South Wales 84: 98 [comb. nov.]

basionym: Encephalartos spiralis var. diplomera F.Muell. legitimate

Johnson, L.A.S. (1961), Zamiaceae. Contributions from the New South Wales National Herbarium, Flora Series 1: 31 [secondary reference]

nomenclatural synonym: Encephalartos spiralis var. diplomera F.Muell. legitimate nomenclatural synonym: Macrozamia spiralis var. diplomera (F.Muell.) A.DC. legitimate pro parte nomenclatural synonym: Macrozamia tridentata f. diplomera (F.Muell.) J.Schust. legitimate

Jacobs, S.W.L. & Pickard, J. (1981), Plants of New South Wales: 5 [secondary reference]

pro parte taxonomic synonym: Macrozamia heteromera C.Moore legitimate pro parte taxonomic synonym: Macrozamia tridentata subsp. cylindrica (C.Moore) J.Schust. legitimate

Harden, G.J. in Harden, G.J. (ed.) (1990), Zamiaceae. Flora of New South Wales 1: 76-77 [secondary reference]

Jones, D.L. (1993), Cycads Of The World: 235 [secondary reference]

Hill, K.D. in McCarthy, P.M. (ed.) (1998), Zamiaceae. Flora of Australia 48: 648, Map 586 [secondary reference]

nomenclatural synonym: Encephalartos spiralis var. diplomera F.Muell. legitimate nomenclatural synonym: Macrozamia spiralis var. diplomera (F.Muell.) A.DC. legitimate nomenclatural synonym: Macrozamia tridentata f. diplomera (F.Muell.) J.Schust. legitimate

• APC Dist.: NSW

Harden, G.J. & Murray, L.J. in Harden, G.J. & Murray, L.J. (ed.) (2000), Flora of New South Wales Supplement 1: 13-14 [secondary reference]

Harden, G.J. in Harden, G.J. (ed.) (2000), Zamiaceae. Flora of New South Wales Revised Edition 1: 76-77 [secondary reference]

Council of Heads of Australasian Herbaria (2006), Australian Plant Census: - APC [secondary reference]

nomenclatural synonym: Encephalartos spiralis var. diplomera F.Muell. legitimate nomenclatural synonym: Macrozamia spiralis var. diplomera (F.Muell.) A.DC. legitimate nomenclatural synonym: Macrozamia tridentata f. diplomera (F.Muell.) J.Schust. legitimate taxonomic synonym: Macrozamia spiralis var. diplomera F.Muell. ex Benth. nom. illeg., nom. superfl.

• APC Dist.: NSW

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