The specific epithet, rigidum, is a Latin adjective derived from the verb, rigidere ("to be stiff") and describes the plant as being "stiff", or "inflexible".[7]
^ abCrisp, M.D. & Weston, P.H. (1987). Stirton, C.H. (ed.). "Cladistics and Legume Systematics, with an analysis of the Bossiaeeae, Brongniartieae and Mirbelieae". Advances in Legume Systematics. 3: 130.{{cite journal}}: CS1 maint: multiple names: authors list (link)