Domin, K. (1927), Beitrage zur Flora und Pflanzengeographie Australiens. Bibliotheca Botanica 22(89): 871 [tax. nov.]

• Type: "Ohne nähere Standortsangabe, MITCHELL 29.XI.1846, Camp 86, No. 615: MITCHELL No. 438; Mt. Remarkable und zwischen diesem und Pentland (DOMIN III. 1910 (♂); Gladstone, Gebüsche am Hange unweite der Küste (DOMIN XII. 1909) (♀ Blüten und Früchte); Gladstone, A. DIETRICH No. 1174 (F♀); Castle Hill bei Townsville (DOMIN II. 1910); Emu Park bei Rockhampton (DOMIN III. 1910); Savannenwälder bei Boonmoo und Mareeba (DOMIN II. 1910), letztere From mit gröβeren, stärker lederigen Blättern; bei Barcaldine (DOMIN III. 1910); Brisbane River, A. DIETRICH No. 1257 (♂); Sunnybank bei Brisbane (DOMIN XII. 1909) (♀, fruchtend); s. l., A. DIETRICH No. 2073 (♀)."

Airy Shaw, H.K. (1976), New or noteworthy Euphorbiaceae. Kew Bulletin 31(2): 368-369 [secondary reference]

• Lectotype: "`Sub Tropical New Holland' (Queensland, W. of Brisbane), 1846, Mitchell 615 or 438, young fruiting specimen (K)."

taxonomic synonym: Petalostigma quadriloculare var. genuina Müll.Arg. nom. inval.

Williams, K.A.W. (1980), Native Plants of Queensland Edn. 2, 1: 226 [secondary reference]

common name: Quinine Bush [n/a] common name: Quinine [n/a]

Airy Shaw, H.K. (26 May 1980), New or noteworthy Australian Euphorbiaceae - II. Muelleria 4(3): 218 [secondary reference]

Airy Shaw, H.K. (November 1980), A partial synopsis of the Euphorbiaceae - Platylobeae of Australia (excluding Phyllanthus, Euphorbia and Calycopeplus). Kew Bulletin 35(3): 663-664 [secondary reference]

taxonomic synonym: Petalostigma quadriloculare var. genuina Müll.Arg. nom. inval.

Airy Shaw, H.K. in Jessop, J.P. (ed.) (1981), Synostemon, Petalostigma. Flora of Central Australia: 194 [doubtful taxonomic synonym]

doubtful taxonomic synonym of: Petalostigma nummularium Airy Shaw legitimate

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. & Leigh, J.H. (1981), Plants of Western New South Wales: 459 [secondary reference]

common name: Quinine [n/a] common name: Downy Cracker-bush [n/a] common name: Native Quince [n/a]

Jacobs, S.W.L. & Pickard, J. (1981), Plants of New South Wales: 117 [secondary reference]

Stanley, T.D. in Stanley, T.D. & Ross, E.M. (1984), Euphorbiaceae. Flora of South-eastern Queensland 1: 426 [secondary reference]

common name: Quinine Berry [n/a]

Green, J.W. (1985), Census of the Vascular Plants of Western Australia Edn. 2: 108 [secondary reference]

Dunlop, C.R. (1987), Checklist of the Vascular Plants of the Northern Territory. Technical Report: Conservation Commission of the Northern Territory 26: 31 [secondary reference]

Floyd, A.G. (1989), Rainforest Trees of Mainland South-eastern Australia: 154 (fig.) [secondary reference]

taxonomic synonym: Petalostigma quadriloculare var. pubescens Müll.Arg. nom. inval. pro parte taxonomic synonym: Petalostigma quadriloculare F.Muell. legitimate

James, T.A. & Harden, G.J. in Harden, G.J. (ed.) (1990), Euphorbiaceae. Flora of New South Wales 1: 402 [secondary reference]

common name: Bitter Bark [n/a]

Wheeler, J.R. in Wheeler, J.R. (ed.) (1992), Euphorbiaceae. Flora of the Kimberley Region: 617, Fig. 189E [secondary reference]

common name: Quinine berry [n/a] common name: Quinine tree [n/a]

Robson, Peter J. (1993), Checklist of Australian Trees: alphabetical listings of common and scientific names: - [secondary reference]

common name: Red hearted Forest Quinine [n/a] common name: Wild Quinine [n/a] common name: Strychnine Tree [n/a] common name: Quinine-tree [n/a] common name: Native Quince [n/a] common name: Forest Quinine [n/a] common name: Downy Cracker Bush [n/a] common name: Bitter Bark [n/a]

Dunlop, C.R., Leach, G.J. & Cowie, I.D. (1995), Flora of the Darwin Region 2: 229 [secondary reference]

common name: Quinine Tree [n/a]

Williams, K.A.W. (1999), Native Plants of Queensland 4: 310 [secondary reference]

common name: Quinine Bush [n/a] common name: Quinine [n/a]

Cooper, W.E. & Cooper, W.T. (2004), Fruits of the Australian Tropical Rainforest: 194-195 [secondary reference]

taxonomic synonym: Petalostigma nummularium Airy Shaw legitimate common name: Witchetty Bush [n/a] common name: Quinine Berry [n/a] common name: Quinine Tree [n/a]

Council of Heads of Australasian Herbaria (2009), Australian Plant Census: - APC [secondary reference]

taxonomic synonym: Petalostigma quadriloculare var. nigrum Ewart & O.B.Davies legitimate taxonomic synonym: Petalostigma nummularium Airy Shaw legitimate

• APC Comment: Petalostigma nummularium is recognised as a distinct taxon in WA and the NT.
• APC Dist.: WA, NT, Qld, NSW

---