Domin, K. (1928), Beitrage zur Flora und Pflanzengeographie Australiens. Bibliotheca Botanica 22(89): 985 [tax. nov.]

• Type: "N.S. Wales; Sandsteinhügel der Blue Mts. nicht selten (DOMIN IV. 1910); Blue Mts., C.T. WHITE in herb. meo; Port Jackson (Georges Head), R. BROWN 1805 als Pombalia crassifolia; R. BROWN, Iter Australiense 1802–05 No. 4951; Blue Mts., A. CUNNINGHAM als Pigea gracilis DC."

Bennett, E.M. (14 November 1972), A revision of the Australian species of Hybanthus Jacquin (Violaceae). Nuytsia 1(3): 234 [taxonomic synonym]

taxonomic synonym of: Hybanthus monopetalus (Schult.) Domin legitimate

Jacobs, S.W.L. & Pickard, J. (1981), Plants of New South Wales: 210 [taxonomic synonym]

taxonomic synonym of: Hybanthus monopetalus (Schult.) Domin legitimate

Adams, L.G. & George, A.S. in George, A.S. (ed.) (1982), Violaceae. Flora of Australia 8: 104 [taxonomic synonym]

taxonomic synonym of: Hybanthus monopetalus (Schult.) Domin legitimate

Stanley, T.D. in Stanley, T.D. & Ross, E.M. (1986), Violaceae. Flora of South-eastern Queensland 2: 100 [taxonomic synonym]

taxonomic synonym of: Hybanthus monopetalus (Schult.) Domin legitimate

Council of Heads of Australasian Herbaria (2005), Australian Plant Census: - [taxonomic synonym]

taxonomic synonym of: Hybanthus monopetalus (Schult.) Domin legitimate

Forster, P.I. (24 March 2021), Reinstatement of Pigea Ging., an earlier generic name for the spade flowers previously included in Afrohybanthus Flicker (Violaceae). Austrobaileya 11: 31 [taxonomic synonym]

taxonomic synonym of: Pigea monopetala (Schult.) Ging. ex DC. legitimate

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