Swartz, O. in Schrader, H.A. (ed.) (1801), Genera et species filicum ordine systematico redactarum adiectis synonymis et iconibus selectis, nec non speciebus recenter detectis, et demum plurimis dubiosis, ulterius investigandis. Journal für die Botanik 1800, 2(1, 2): 93 [comb. nov.]

basionym: Polypodium extensum G.Forst. legitimate

Cretzoiu, P. (1941), Die bisher aus Australien, Ozeanien und Asien bekannt gewordenen Arten der Gattung Cyathea J.E.Sm. Feddes Repertorium Beiheft 50(20-25): 304 [secondary reference]

• Text: "Polynesia, Nova Guinea, Ins. Norfolk, Isle of Pine, Sandwich, Australia."

Tindale, M.D. (26 June 1956), The Cyatheaceae of Australia. Contributions from the New South Wales National Herbarium 2(4): 360 [secondary reference]

• Text: "Cretziou in Fedde Repert., L.(1941), 304, records Cyathea extensa (Forst. f.) Sw., from Australia. I have examined Forster's and Swart'z type material of this species in the Riksmuseum, Stockholm, but I have never seen any Australian material of this species."

Bostock, P.D. in McCarthy, P.M. (ed.) (1998), Cyatheaceae. Flora of Australia 48: 205 [secondary reference]

• Text: "Excluded from the Australian flora by M.D.Tindale, Contr. New South Wales Natl. Herb. 2: 360 (1956)."

Council of Heads of Australasian Herbaria (31 July 2018), Australian Plant Census: - APC [secondary reference]

nomenclatural synonym: Polypodium extensum G.Forst. legitimate

• APC Comment: A name of uncertain application.

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