Gardner, C.A. (1936), Contributiones Florae Australiae Occidentalis, IX. Journal of the Royal Society of Western Australia 22: 125 [tax. nov.]

• Type: "Austin district, at the northern base of Mount Singleton, in red stony soil, fl. m. July, in shady spots. W.E. Blackall and C.A. Gardner, 9th July, 1931. ... The type is Gardner 2212, in the State Herbarium."

Bennett, E.M. (14 November 1972), A revision of the Australian species of Hybanthus Jacquin (Violaceae). Nuytsia 1(3): 231, Fig. 8 (map) [secondary reference]

Adams, L.G. & George, A.S. in George, A.S. (ed.) (1982), Violaceae. Flora of Australia 8: 106, Map 114 APC [secondary reference]

• APC Dist.: WA

Green, J.W. (1985), Census of the Vascular Plants of Western Australia Edn. 2: 118 [secondary reference]

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: 29 [basionym]

basionym of: Pigea cymulosa (C.A.Gardner) P.I.Forst. legitimate

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