Reynolds, S.T. & Henderson, R.J.F. (11 December 2001), Vanguerieae A.Rich ex Dum. (Rubiaceae) in Australia, 2. Cyclophyllum Hook.f. Austrobaileya 6(1): 52-53, Fig. 3, Map 3 APC [primary reference]

• Type: [New South Wales.] Port Jackson, February 1805, R. Brown s.n. (holo: MEL [MEL1538081]; iso: ?BM n.v., BRI [AQ123681], CANB, NSW [NSW193831]).

taxonomic synonym: Canthium sp. (Cooroy S.T.Blake+ 15507) [n/a]

• APC Dist.: Qld, NSW

• Etymology: The specific epithet, from Latin longus, long, and petalum, petal, refers to the comparatively long corollas in flowers of this species.

Henderson, R.J.F. in Henderson, R.J.F. (ed.) (2002), Postscript. Names and Distribution of Queensland Plants, Algae and Lichens: 282 [secondary reference]

taxonomic synonym: Canthium sp. (Cooroy S.T.Blake+ 15507) [n/a]

National Herbarium of New South Wales (2009), PlantNET Flora of New South Wales Online: - [secondary reference]

common name: Coast Canthium [n/a]

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