A small herb, Sauvagesia erecta (family Ochnaceae), with solitary white, pink, or purple five-petalled flowers, native to tropical America and West Africa; also called St Martin's herb.
Origin
Early 19th century.
Definition of iron shrub in US English:
iron shrub
noun
rare
A small herb, Sauvagesia erecta (family Ochnaceae), with solitary white, pink, or purple five-petalled flowers, native to tropical America and West Africa; also called St Martin's herb.