Maiden, J.H. in Ewart, A.J. & Davies, O.B. (1917), Appendix IV: Acacias of the Northern Territory. The Flora of the Northern Territory: 344, pl. 27I-O [tax. nov.]

• Type: Howard Creek, 15th June, 1916 (G.F. Hill) (In flower). Co-types are Nos. 578 and 598.

Specht, R.L. in Specht, R.L. & Mountford, C.P. (ed.) (August 1958), The Gymnospermae and Angiospermae collected on the Arnhem Land Expedition. Records of the American-Australian Scientific Expedition to Arnhem Land No. 3 Botany and Plant Ecology: 235 [secondary reference]

Chippendale, G.M. (17 April 1972), Check List of Northern Territory Plants. Proceedings of the Linnean Society of New South Wales 96(4): 236 [secondary reference]

Pedley, L. (7 May 1981), Further notes on Acacia in Queensland. Austrobaileya 1(4): 340-341 [secondary reference]

Dunlop, C.R. (1987), Checklist of the Vascular Plants of the Northern Territory. Technical Report: Conservation Commission of the Northern Territory 26: 49 [secondary reference]

Pedley, L. (24 September 1987), Racosperma Martius (Leguminosae: Mimosoideae) in Queensland: a checklist. Austrobaileya 2(4): 348 [basionym]

basionym of: Racosperma difficile (Maiden) Pedley legitimate

Green, J.W. (18 October 1987), Census of the Vascular Plants of Western Australia Edn. 2, Suppl. 5: 8 [secondary reference]

Wheeler, J.R. in Wheeler, J.R. (ed.) (1992), Mimosaceae. Flora of the Kimberley Region: 299-301 [secondary reference]

nomenclatural synonym: Racosperma difficile (Maiden) Pedley legitimate

Dunlop, C.R., Leach, G.J. & Cowie, I.D. (1995), Flora of the Darwin Region 2: 8, Fig. 2 [secondary reference]

Tindale, M.D. & Kodela, P.G. in Orchard, A.E. & Wilson, A.J.G. (ed.) (2001), Flora of Australia 11B: 188, Fig. 40J-M, Map 260 APC [secondary reference]

• Type: Howard Ck, 20 miles [32 km] SE of Darwin, N.T., 15 June 1916, G.F.Hill ; syn: NSW240680.

nomenclatural synonym: Racosperma difficile (Maiden) Pedley legitimate pro parte taxonomic synonym: Acacia tumida F.Muell. ex Benth. legitimate

• APC Dist.: WA, NT, Qld

Maslin, B.R. (9 July 2001), Wattle - Acacias of Australia: - [secondary reference]

nomenclatural synonym: Racosperma difficile (Maiden) Pedley legitimate pro parte taxonomic synonym: Acacia tumida F.Muell. ex Benth. legitimate

McDonald, M.W. (13 May 2003), Revision of Acacia tumida (Leguminoseae: Mimosoideae) and close allies, including the description of three rare taxa. Australian Systematic Botany 16(2): 145-147, Figs 4, 5 (map) [secondary reference]

pro parte nomenclatural synonym: Acacia tumida F.Muell. ex Benth. legitimate

• APC Comment: Natural hybrids are recorded between A. difficilis and A. tumida, A. mountfordiae and A. torulosa (McDonald, 2003).
• APC Dist.: WA, NT, Qld

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